Tag Archive for: tool coatings

The Advantageous Qualities of Helical Solutions’ Nplus Coating

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When it comes to machining difficult materials like high-silicon aluminums, abrasive copper alloys, and other non-ferrous and aluminum alloys, finding a coating that improves performance and increases tool life can be difficult. When machining in aluminum-based materials, machinists often opt for an uncoated tool due to the sharp cutting edge needed. Uncoated tools may give you the sharpest edge possible, but Helical’s Nplus coating helps combat wear and keep your edge sharp for longer, allowing you to win at the spindle and gain a competitive edge.  

What is Helical Solutions’ Nplus Coating?

Helical’s Nplus coating is applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a near-vacuum and distributes micron-thick layers evenly onto a properly prepared tool.

For more information on the PVD coating process, read PVD Coating vs. CVD: Two Common Coating Application Methods.

Nplus is a premium coating, specially engineered to extend tool life when machining non-ferrous and aluminum alloys. 

nplus coating chart
The above image was taken from Helical Solutions’ Coating Chart.

When Should a Machinist Use Nplus Coating?

When Machining Non-ferrous and Aluminum Alloys

Helical’s Nplus coating is optimized for machining difficult aluminum alloys and other abrasive non-ferrous materials, as its composition doesn’t react with aluminum as some other coatings do. This coating possesses many advantageous qualities, including its high hardness (40 GPa), which provides excellent edge retention to ensure that your tool stays sharp for longer. Also, its high working temperatures (2,012°) and its thickness (1-4 µm) provide further wear resistance when tackling these difficult-to-machine materials.

Nplus coated Helical end mills

When Working in High Temperature Non-Ferrous Applications

When machining in many non-ferrous and aluminum alloys, high temperatures can become an issue. Nplus is specially designed to withstand temperatures up to 2,012°, allowing tooling to run at the high temperatures these abrasive materials require, without degrading them.

When Machining Large Production Runs

Machining materials like wrought aluminum, cast aluminum, graphite, and other non-ferrous alloys can quickly end the life of your tool, costing time and money. Nplus coating is specially engineered to extend tool life in these materials, allowing your tool to stay in the spindle for longer. This calls for less tool changes, creating a more efficient process flow in your large production runs.

Helical’s Nplus Coated Tooling

Helical’s 5 Flute End Mills for Aluminum

Introduced in Helical’s Spring 2022 Catalog, Helical’s 5 Flute End Mills for Aluminum are specially engineered for optimal performance in High Efficiency Milling (HEM) of aerospace aluminum alloys and other non-ferrous alloys. They’re offered in two unique styles, both fully stocked in Helical’s Nplus coating:

5 Flute – Corner Radius  – Variable Pitch – Chipbreaker Rougher

5 Flute – Corner Radius – Variable Pitch – End Mill

Helical’s Multi-Axis Finishers for Aluminum

Also introduced in Helical’s Spring 2022 catalog, this offering of Multi-Axis Finishers feature a specially defined profile for massive reductions in cycle times and vastly improved surface finish when machining aluminum.  They’re offered in 3 styles, all fully stocked in Helical’s Nplus coating to ensure excellent finish in abrasive aluminums and extended tool life in a wide variety of non-ferrous materials.

Multi-Axis Finishers – 3 Flute – Lens Form

Multi-Axis Finishers – 4 Flute – Taper Form

Multi-Axis Finishers – 4 Flute – Oval Form

For more information on Helical Solutions’ coatings, visit https://www.helicaltool.com/resources/tool-coatings.

PVD Coating vs. CVD: Two Common Coating Application Methods

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Most tool manufacturers offer tool coatings, made up of a layer of metal compounds adhered to the surface of the tool to enhance its performance. The most common methods for adding coatings to a tool are Physical Vapor Deposition (PVD coating) and Chemical Vapor Deposition (CVD coating). This article will take a deep dive into PVD vs CVD to identify their unique and shared characteristics.

Physical Vapor Deposition (PVD) Coatings

The PVD coating method is a process in which metals go through a cycle of vaporization and condensation to be transferred from their original solid state to the tool. The metal compounds that make up the coatings are often referred to as the “metal material” in this process. The metal material starts as a solid wafer and is vaporized into a plasma, which can then be put onto the tools in the chamber. In this process, the tools are referred to as the “substrate.”

There are two different ways in which PVD coatings can be performed: arc ion plating and sputtering.

Arc Ion Plating & Sputtering

Key Differences

The main difference between arc ion plating and sputtering is that arc ion plating uses high electrical currents to vaporize the metallic material, and the metal ions are steered onto the tool for coating. Sputtering, in contrast, uses the properties of magnetic fields to direct reactive gasses to collide with a target made up of metallic material. During these collisions, metallic surface ions fall from the target and land on the substrate, slowly bombarding it until it is sufficiently coated. Both arc ion plating and sputtering are high temperature, ultrahigh vacuum processes. The term “vacuum” refers to any pressure below atmospheric pressure at sea level.

Above is an example of a Harvey Tool AlTiN Coated tool, which is applied using a PVD process.

Application Processes of Arc Ion Plating & Sputtering

Arc Ion Plating

  1. The internal pressure within the reaction chamber is dropped to form a vacuum to around 1 Pa (0.0000145 psi). Creating a vacuum is crucial as it removes any moisture and impurities, on or surrounding the tools.
  2. The chamber is heated to temperatures ranging from 150 – 750°C (302 – 1382°F). The temperature of the chamber is dependent on the coating that is being applied to create an ideal chemical reaction and adhesion between the plasma and substrate. A high current of around 100 A is applied to the metallic material causing an explosive reaction.
  3. The high current positively ionizes the metal and vaporizes it into a dense plasma.
  4. The substrate is negatively charged to attract the positive metal ions.
  5. The ions collide into tools with force and are deposited, forming a film that builds up in thickness to create the desired coating.

Sputtering

  1. The internal pressure within the reaction chamber is dropped to form a vacuum to around 1 Pa (0.0000145 psi) to remove any moisture and impurities on or surrounding the tools.
  2. An inert gas is pumped into the chamber to create a low pressure atmosphere. Inert gases are specifically used, as it is non-reactive with the metal elements and ensures that impurities are not mixed in with the tool coatings.
  3. The gas used is dependent on the atomic weight of the metal material; a heavier gas is commonly used with heavier metals.
  4. The chamber is heated to temperatures anywhere from 150 – 750°C (302 – 1382°F) depending on the coating that is being applied.
  5. The tools are placed between the metallic materials (called the “target” in sputtering) and an electromagnet, so that when turned on, a magnetic field runs along and around the tools.
  6. A high voltage is then applied along the magnetic field ionizing the argon atoms.
  7. Voltage ranges from 3-5 kV, and if using AC, with a frequency of around 14 MHz.
  8. The target is negatively charged attracting the positively charged Argon gas.
  9. The inert gas collides with the target ejecting metallic compounds onto the substrate to create a coating.

Key PVD Coating Differences, Summarized

Arc ion plating and sputtering are both effective methods of applying a PVD coating. So why use one over the other? Arc ion plating has a significantly higher ionization rate than sputtering, allowing for much faster deposition rates, shortening coating times. In turn, since sputtering is a slower process, it allows for more control when applying multi-metal compositions and ensuring that the stoichiometry of the coating is even throughout the tool. Finally, during the PVD coating process, micro-droplets are formed as the vaporized metals condense and solidify onto the tools. As these droplets impact the newly applied coating, they can cause defects and craters, producing residual stress points. In order to achieve a perfect coating, droplet size must be minimized. Arc ion plating produces droplets up to 3µm (micrometers) in diameter, while sputtering has droplets with diameters up to 0.3µm. With droplets up to ten times smaller, sputtering produces much smoother and defect-free surfaces which have been proven to slow corrosion rates.

Chemical Vapor Deposition (CVD)

PVD coating vs CVD Coated Tool
Above is an example of a Harvey Tool CVD Ball End Mill.


Unlike PVD coating operations, which use high electrical charges and atomic collisions to deposit coatings onto a tool, the CVD method utilizes the chemical properties of the metals to transfer metallic compounds onto the tool. The following steps are required to carry out the CVD operation:

  1. Much like the PVD method, the first step is creating an ultrahigh vacuum within the reaction chamber of around 1 Pa (0.0000145 psi) to eliminate all moisture and impurities.
  2. The internal temperature of the chamber is increased between 600 – 1000°C (1112 – 2012°F).
  3. The temperatures required in the CVD process are significantly higher than PVD coating because this method requires a chemical reaction to occur between gases flowed into the chamber and the substrate. High temperatures are required to initiate and maintain these reactions.
  4. Once the substrate is heated to its desired temperature, the metals intended to be coated onto the tools, which are already in their vapor state, are chemically bonded with a reactive gas (typically chlorine), and flowed into the chamber.
  5. The metallic materials being bonded to a gas keeps it in a gaseous state while it is being transported through the chamber and around the tools.
  6. Hydrogen gas is then pumped into the chamber and mixes with the chlorine and metals.
  7. When this mixture meets the heated substrate, the thermal energy creates a reaction where hydrogen and chlorine bond and leave the metallic materials behind on the tools.
  8. In the chamber, there is an exit vent where the waste gas (H2Cl) is removed.

PVD Coating & CVD Coating, Summarized

Tool coatings are utilized by machinists every day to accomplish prolonged tool life, a more efficient machining operation, and an overall higher quality final part. Most manufacturers use two different types of application techniques, PVD coating and CVD coating. Stay on “In the Loupe” to learn more about tool coatings by reading the following blog posts: Overview of Harvey Tool Coatings: Maximizing Performance and 3 Ways Tool Coatings Increase Tool Life.

Citation:
[1] Ucun, İ., Aslantas, K., & Bedir, F. (2013). An experimental investigation of the effect of coating material on tool wear in micro milling of Inconel 718 super alloy. Wear, 300(1-2), 8–19. https://doi.org/10.1016/j.wear.2013.01.103

3 Ways Tool Coatings Increase Tool Life

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Cutting tools are commonly found with an ultra-thin molecular compound coating applied to its cutting surfaces. These coatings are engineered to combat against forces that wear down your cutting tools and lead to catastrophic tool failure. Not only are coatings created for cutting specific materials, but they also limit heat and friction and enhance the performance of your tool. When selecting a coated tool, the machinist must consider how the material and desired cutting operations may break down the cutting edges of the tool, to determine which coating will best serve their needs. Before those decisions can be made, one must understand how coatings increase a tool’s cutting abilities. The following is an in-depth look into the benefits provided by tool coatings and how they work to improve tool life and performance.

What Is a Coating?

Tool coatings consist of organic and inorganic compounds which are applied and adhered onto the substrate using Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD). Compounds are deposited onto the tools in layers until a desired thickness is achieved.

Coated cutting tools provide three main functions:

  1. Provide a thermal barrier between the tool and workpiece
  2. Improve tool lubricity
  3. Increase tool wear resistance

With the proper utilization of these three features, cutting tools can be pushed much harder, run with faster cycle times, and last longer.

1.      Provide a Thermal Barrier Between the Tool and Workpiece

Heat mitigation is essential in machining, as excessive tool and workpiece heating during cutting operations can be detrimental. As the carbide tool’s temperature rapidly increases, its hardness decreases, resulting in greater wear and burn out. Thermal conductivity is a material property used to measure a material’s ability to retain or transfer heat energy. For example, tungsten carbide has a thermal conductivity of 88 W/m.K at 20°C. This means at room temperature, 20°C (68°F), an uncoated carbide tool can conduct 88 Watts of thermal energy per meter with a temperature gradient measured in Kelvin. The materials used in tool coatings do not conduct heat as well with thermal conductivity rates as low as 4.5 W/m.K. This means that a coating with a thermal conductivity of 4.5 W/m.K, the coating would transfer 19.56 times less heat than tungsten carbide.

An experiment showcasing the thermal abilities of coatings is shown below. Both an AlTiN Nano coated tool and uncoated tool were turning 4340 steel at a speed of 155 m/min (508.5 ft/min) and 200 m/min (656.17 ft/min), at a feed rate on 0.5 mm/rev (0.019 in/rev) and a depth of cut of 3.5 mm (0.138 in) [1]. No coolant was used.

uncoated tool thermal gradient

Figure 1: Thermal gradient of the cutting tip of the uncoated tool [1].

tool coatings thermal gradient

Figure 2: The above images, found in a study titled “Experimental Study and Modeling of Steady State Temperature Distributions in Coated Cemented Carbide Tools in Turning,” written by Amol Thakare and Anders Nordgren, showcase the effects of cutting tool speed and tool deformation on temperature distributions in unworn (left) and worn (right) tool.

Comparing the two tools, it is clear that the coated tool absorbs far less heat than the tool without a coating. With lower thermal conductivity rates, tool coatings create a thermal barrier between the carbide and workpiece. This greatly decreases the internal temperature of the carbide as the heat generated during the cutting operations is redirected into the chips and workpiece. With lower temperatures, faster cutting speeds can be attained. Looking at the thermal gradients above, the uncoated tool running at 155 m/min and the coated tool running at 200 m/min roughly have the same surface temperature. This means the coated tool can run 22.5% faster than its uncoated counterpart.

2. Coatings Increase Tool Lubricity

Another key to limiting heat generation and keeping cutting smooth and chatter-free is to decrease the amount of friction between the cutting tool and workpiece. Frictional force is the resistance to motion, and in the case of cutting tools, the force opposing the lateral and radial movements of the tools as it cuts through the workpiece. This opposing force is determined by the coefficient of friction, often denoted as the Greek letter Mu (μ). The friction coefficient is the ratio between the force required to move one surface across another, divided by the pressure between the two surfaces. Minimizing μ is how coatings decrease the overall frictional forces involved in cutting operations because the force of friction is directly proportional to μ.

An example to show how much a coating can reduce the coefficient friction during cutting operations, over an uncoated carbide tool, is shown in the study performed by the University of Technology of Malaysia. In this experiment, 1040 carbon steel was turned at 60 mm/min (2.36 in/min), a depth of cut of 1 mm (0.04 in), a feed rate of 0.06 mm/rev (0.0024 in/rev), and a repeated length of cut of 100 mm (3.937 in) until the tool cut a total length of 1000 m (3280.84 ft) [2]. The coated tool had a TiCN coating, a coating similar to the more popular AlTiN coating. Below are the results:

Figure 3: The above image, found in “Friction and Wear Characteristics of WC and TiCN-coated Insert in Turning Carbon Steel Workpiece,” displays the friction coefficient of the TiCN coated tool and uncoated tungsten carbide tool.

As seen in figure 3, the TiCN coated tool had a much lower coefficient of friction than the uncoated tool. This lower coefficient decreases the frictional forces experienced during cutting operations, reducing heat generation, giving a better part finish, and extending tool life.

Selecting a coated tool with high lubricity would also be ideal for cutting materials with low melting temperatures, as well as materials that generate a tremendous amount of heat during machining, such as high hardness alloys. In materials with low melting points (such as aluminum or other non-ferrous metals), high friction can cause heat generation and sticking of chips. These chips can then cause chip packing in flute valleys and galling on the cutting edge. This galling is called built up edge (BUE) which creates a thicker edge and can break down the tool. With lower friction coefficients, it is more difficult for chips to stick to the tool and for BUE to occur. When cutting materials that would generate high temperatures (such as stainless steels and aerospace alloys), keeping frictional forces at a minimum, will reduce heat generation, and result in smoother cutting, preserving the tool’s cutting edges.

3.      Tool Coatings Increase Tool Wear Resistance

Adding a coating with a high microhardness rating increases a cutting tool’s ability to resist wear and avoid permanent deformations. In the cutting industry, cutting tool grades for tungsten carbide range from grades C1 to C14, depending on what the cutting operation the tool will be performing. Between grades C1 to C14, tungsten carbide has a Vickers Hardness (HV) ranging from 760 HV to 1740 HV. Tool coatings have higher microhardness ratings than tungsten carbide. Adding a coating can increase a tool’s hardness anywhere from 2213 HV using a TiN coating, to 9993 HV with the CVD diamond coating. While a TiN coating would not be chosen solely for its hardness, it shows that even the coating with the lowest hardness is still harder than bare tungsten carbide. By making the cutting tool significantly harder, the ratio of workpiece hardness to tool hardness increases. Increasing the tool’s hardness will allow it to shear off chips and remove material with greater ease, especially against high abrasive materials, while the tool maintains its structural integrity against the extreme forces experienced during cutting operations.

The benefits of increasing tool hardness with its improved performance are demonstrated in an experiment done by Afyon Kocatepe University. In this experiment, a 2 flute micro end mill with a cutting diameter of 4 mm was slotting into Inconel 718 at 20,000 rpm, with a feed rate of 5 micrometers per flute, a depth of cut of 0.2 mm and a length of cut of 120 mm [3]. This cut was performed using both an uncoated and AlTiN coated (3620 HV hardness) carbide end mill with no coolant. Below are optical comparator images of the two tools showing their wear and deformations.

Figure 4: The image above from “An Experimental Investigation of the Effect of Coating Material on Tool Wear in Micro Milling of Inconel 718 Super Alloy,” showcases an uncoated cutting tool.

Figure 5: The image aboves from “An Experimental Investigation of the Effect of Coating Material on Tool Wear in Micro Milling of Inconel 718 Super Alloy,” showcases the difference a coating can make on a cutting tool. Figure 4 displays an uncoated cutting tool, and figure 5 displays a cutting tool with AlTiN PVD coating.

Looking at the two tools, it is evident that the uncoated tool experienced significant flank and crater wear, which resulted in the flaking of its cutting edges. As this tool performed its cuts, flank wear occurred first. This wear happened directly at the cutting edge as the abrasive Inconel alloy began to breakdown the tool. As the flank wear increased past the cutting edge and into the rake face of the tool, crater wear formed. Crater wear is characterized by its depth into the tool. As chips slid across the rake face and increased this crater, pieces of the carbide tool began to flake off, forming a new, weaker cutting edge. This new edge is blunt and will not be capable for cutting the workpiece properly, and will continue to break apart until catastrophic tool failure occurs.

Flank and crater wear are two types of mechanical tool decay that are a direct result of the abrasiveness of the workpiece material. Increasing the microhardness of the cutting tool can combat against these abrasive modes of tool wear. This is proven in figure 5, as the AlTiN PVD coated end mill held up much better in comparison to the uncoated tool as it experienced minimal flank wear. As the coated tool performed its cuts, the only detectable wear was a microfracture along one of its cutting edges, and peeling of the AlTiN coating. The protection provided by the coating against abrasive wear is evident in this example, and with this protection, tool life is significantly increased.

The Benefit of Tool Coatings During Machining

Combining the three main advantages of a tool coating, thermal resistance, increased lubricity, and higher microhardness, not only does the tool perform better, but it lasts longer. Minimizing thermal and abrasive tool wear can substantially prolong tool life.

Citations

      [1] Thakare, Amol, and Anders Nordgren. “Experimental Study and Modeling of Steady State Temperature Distributions in Coated Cemented Carbide Tools in Turning.” Procedia CIRP, vol. 31, 2015, pp. 234–239., doi:10.1016/j.procir.2015.03.024.

      [2] Talib, R.J., et al. “Friction and Wear Characteristics of Wc and Ticn-Coated Insert in Turning Carbon Steel Workpiece.” Procedia Engineering, vol. 68, 2013, pp. 716–722., doi:10.1016/j.proeng.2013.12.244.

[3] Ucun, İ., Aslantas, K., & Bedir, F. (2013). An experimental investigation of the effect of coating material on tool wear in micro milling of Inconel 718 super alloy. Wear, 300(1-2), 8–19. https://doi.org/10.1016/j.wear.2013.01.103

Harvey Tool Coatings: Maximizing Tool Performance

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Proper tool coating plays a large role during the selection of a CNC cutting tool. At Harvey Tool, coatings are optimized for specific materials and alloys to ensure the highest tooling performance, possible. Each coating offers a unique benefit for the cutting tool: increased strength, enhanced lubricity, heat resistance, and wear mitigation, just to name a few.  

In Benefits of Tool Coatings, the method of applying coatings to tools is examined. In this post, we’ll take a closer look at each Harvey Tool coating to examine its key properties, and to help you decide if it might add a boost to your next CNC application.

Harvey Tool offers a wide range of tool coating options for both ferrous and exotic materials, as well as non-ferrous and non-metallic materials. In the Harvey Tool catalog, coatings are often denoted in a -C# at the end of the product part number.

Harvey Tool Coating Gallery

Harvey Tool Coatings for Ferrous and Exotic Materials

TiN

TiN, or Titanium Nitride (-C1), is a mono-layer coating meant for general purpose machining in ferrous materials. TiN improves wear resistance over uncoated tools and aids in decreasing built-up edge during machining. This coating, however, is not recommended for applications that generate extreme heat as its max working temperature is 1,000 °F. TiN is also not as hard as AlTiN and AlTiN Nano, meaning its less durable and may have a shorter tool life.

Harvey Tool 46062 Tin Tool Coating

Harvey Tool 46062-C1

AlTiN

AlTiN, or Aluminum Titanium Nitride (-C3), is a common choice for machinists aiming to boost their tool performance in ferrous materials. This coating has a high working temperature of 1,400 °F, and features increased hardness. AlTiN excels in not only dry machining, due to its increased lubricity, but also in machining titanium alloys, Inconel, stainless alloys, and cast iron. To aid in its high heat threshold, the aluminum in this coating coverts to aluminum oxide at high temperatures which helps insulate the tool and transfer its heat into the formed chips.

altin tool coating 823816-C3

Harvey Tool 823816-C3

AlTiN Nano

AlTiN Nano or Aluminum Titanium Nitride Nano (-C6) is Harvey Tool’s premium coating for ferrous applications. This coating improves upon AlTiN by adding silicon to further increase the max working temperature to 2,100 °F while also increasing its hardness for increased tool life during demanding applications. Due to its penchant for demanding applications, AlTiN is recommended for hardened steels, hardened stainless, tool steels, titanium alloys, and aerospace materials. These applications often create high levels of heat that AlTiN Nano was designed to combat.

altin nano tool coating

Harvey Tool 843508-C6

harvey tool coating zoomed in

Tool Coatings for Non-Ferrous and Non-Metallic Materials

TiB2

TiB2, or Titanium Diboride (-C8), is Harvey Tool’s “bread and butter” coating for non-abrasive aluminum alloys and magnesium alloys, as it has an extremely low affinity to aluminum as compared to other coatings. Aluminum creates lower working temperatures than ferrous materials, so this coating has a max working temperature of of a suitable 900 °F. TiB2 prevents built-up edge and chip packing, further extending its impressive tool life. TiB2 is not recommended for abrasive materials as the carbide is slightly weakened during the coating process. These materials can cause micro fractures that may damage the tool at high RPMs.

TiB2 can be found on a wide variety of Harvey Tool 2 and 3 flute tools as the premium option for high performance in aluminum alloys.

tib2 tool coating

Harvey Tool 820654-C8

ZrN

ZrN, or Zirconium Nitride (-C7), is a general-purpose coating for a wide variety of non-ferrous materials, including abrasive aluminum alloys. This tool coating is a lower cost alternative to diamond coatings, while still boasting impressive performance through its high hardness levels and overall abrasion resistance. ZrN has a max working temperature of 1,110 °F with strong lubricity in abrasive alloys. This coating is best suited for abrasives, such as brass, bronze, and copper, as well as abrasive aluminum alloys that should not be used with TiB2.

zrn tool coating

Harvey Tool 27912-C7

CVD Diamond Tool Coatings

CVD Diamond, or Crystalline CVD Diamond, is a process where the coating is grown directly onto the carbide end mill. This process dramatically improves hardness over other coatings, improving tool life and abrasion resistance while also allowing for higher feed rates. The trade-off for increased wear resistance is a slight rounding of the cutting edge due to the coating application. Due to its increased wear resistance, CVD is best suited for highly abrasive materials such as graphite, composites, green carbide, and green ceramics. Similarly, these tool coatings have a max working temperature of 1,100 °F, meaning they are not well suited for ferrous applications.

Harvey Tool’s CVD Diamond Coating Options:

diamond tool coatings
Amorphous, CVD 4 μm, CVD 9 μm, PCD Diamond

CVD Diamond (4 μm)

The 4 μm is thinner than the 9 μm allowing for a sharper cutting edge, which in effect leaves a smoother finish.

CVD Diamond 9 μm)

The 9 μm CVD tool coating offers improved wear resistance over the 4 μm CVD and Amorphous coatings due to its increased coating thickness.

Amorphous Diamond

Amorphous Diamond (-C4) is a PVD diamond coating which creates an exceptionally sharp edge as compared to CVD. This coating aids in performance and finish in abrasive non-ferrous applications, as it allows for greatly improved abrasion resistance during machining, while still maintaining a sharp cutting edge necessary for certain abrasives. Due to the thinness of the coating, edge rounding is prevented in relation to CVD diamond tooling. Amorphous Diamond is best suited for use in abrasive plastics, graphite, and carbon fiber, as well as aluminum and aluminum alloys with high silica content, due to their abrasiveness. The max working temp is only 750 °F, so it is not suited for use in ferrous machining applications.

Harvey Tool 809362-C4

PCD Diamond

PCD Diamond, or Polycrystalline Diamond, is a tool coating that is brazed onto the carbide body. In comparison to the other diamond coatings, PCD does not face the same challenges of other coatings as it pertains to rounded cutting edges, as these edges are ground sharp. PCD has the edge benefits of Amorphous Diamond with the abrasion resistance of CVD Diamond. PCD is the thickest diamond layer offered by Harvey Tool, and excels due to its incredible hardness and abrasion resistance. This tool is best suited for all forms of abrasive, non-ferrous materials including abrasive plastics, graphite, carbon fiber, and composites. Similar to the other non-ferrous tool coatings, PCD is not suited for ferrous applications due to its working temperature of 1,100 °F.

pcd diamond

Harvey Tool 12120

Tool Coating Summary

When deciding on a coating for your application there are many factors to be considered. Different coatings often cross several applications with performance trade-offs between all of them. Harvey Tool offers a “Material Specific Selection” that allows users to choose tooling based upon what materials they are working with. Further, Harvey Tool’s technical team is always a phone call away to help in finding the right tool for your specific applications at 1-800-645-5609. Also, you can contact Harvey Tool via e-mail.

An In-Depth Look at Helical’s Tplus Coating for End Mills

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When working with difficult-to-machine materials, such as Inconel, stainless steel, or hardened steels, utilizing an effective coating is important for sustaining the life of your tool and perfecting the outcome of your part. While looking for the right coating, many machinists try out several before finding a solution that works – a process that wastes valuable time and money. One coating gaining popularity in applications involving tough materials is Helical Solutions’ Tplus coating. This post will explore what Tplus coating is (and isn’t), and when it might be best for your specific job.

tplus coating on helical end mill

What is Helical Solutions’ Tplus Coating?

Helical’s Tplus coating is a Titanium-based, multi-layered coating that is applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a near-vacuum and distributes micron-thick layers evenly onto a properly prepared tool.  Tplus is a premium, multi-layered, titanium coating that increases edge strength, wear resistance, and tool life.

tplus coating specification chart

When Should a Machinist Use Tplus Coating?

When Working in Difficult to Machine Materials

Tplus coating works great in difficult-to-machine materials such as Inconel, stainless steel, hardened steels, and other alloyed steels with a hardness up to 65 Rc. It provides high hardness (44 GPa) for your tool, creating stronger cutting edges and resulting in extended tool life.

When Working in High Temperature Applications

When you are running an application in a ferrous material where extreme heat and work hardening are a possibility, Tplus is a great solution, as it’s designed to withstand high temperatures (up to 2,192°).

Helical Solutions’ 7 Flute Tplus End Mill

In Dry Machining Applications

In the absence of coolant, fear not! Tplus coating is a viable option since it can handle the heat of machining. The low coefficient of friction (0.35) guarantees great performance in dry machining and allows the coated tool to move throughout the part smoothly, creating less heat, which is extremely beneficial in applications without coolant.

In Large Production Runs

In high production runs is truly where this coating excels, as its properties allow your tool to remain in the spindle longer – creating more parts by avoiding time in swapping out a worn tool.

What to Know About Helical Solution’s Zplus Coating

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Non-ferrous and non-metallic materials are not usually considered difficult to machine, and therefore, machinists often overlook the use of tool coatings. But while these materials may not present the same machining difficulties as hardened steels and other ferrous materials, a coating can still vastly improve performance in non-ferrous applications. For instance, materials such as aluminum and graphite can cause machinists headaches because of the difficulty they often create from abrasion. To alleviate these issues in non-ferrous machining applications, a popular coating choice is Helical Solution’s Zplus coating.

zplus coating

What is Helical Solutions’ Zplus Coating?

Helical’s Zplus is a Zirconium Nitride-based coating, applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a vacuum and forms layers only microns thick onto the properly prepared tool. Zirconium Nitride does not chemically react to a variety of non-ferrous metals, increasing the lubricity of the tool and aiding in chip evacuation.

zplus coating specification chart

When Should a Machinist Use Helical Solution’s Zplus?

Working with Abrasive Materials

While Zplus was created initially for working in aluminum, its hardness level and maximum working temperature of 1,110°F enables it to work well in abrasive forms of other non-ferrous materials, as well. This coating decreases the coefficient of friction between the tool and the part, allowing it to move easier through more abrasive materials. This abrasion resistance decreases the rate of tool wear, prolonging tool life.

Concerns with Efficient Chip Evacuation

One of the primary functions of this coating is to increase the smoothness of the flutes of the tool, which allows for more efficient chip removal. By decreasing the amount of friction between the tool and the material, chips will not stick to the tool, helping to prevent chip packing. The increased lubricity and smoothness provided by the coating allows for a higher level of performance from the cutting tool. Zplus is also recommended for use in softer, gummy alloys, as the smooth surface encourages maximum lubricity within the material – this decreases the likelihood of those gummier chips sticking to the tool while machining.

Large Production Runs

Uncoated tools can work well in many forms of non-ferrous applications. However, to get a genuinely cost-effective tool for your job, the proper coating is highly recommended. Large production runs are known for putting a lot of wear and tear on tools due to their increased use, and by utilizing an appropriate coating, there can be a significant improvement in the tools working life.

3 flute corner radius end mill for aluminum

When is Zplus Coating Not Beneficial to My Application?

Finishing Applications

When your parts finish is vital to its final application, a machinist may want to consider going with an uncoated tool. As with any coating, ZrN will leave a very minor rounded edge on the tip of the cutting edge. The best finish often requires an extremely sharp tool, and an uncoated tool will have a sharper cutting edge than its coated version.

What to Know About Harvey Tool’s TiB2 Coating

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Aluminum and magnesium alloys are common materials found in machine shops worldwide, and are known as an “easier” material to machine. However, machinists can still experience hiccups while machining this material if they are not prepared with the proper tooling.. When working with aluminum and magnesium alloys, it is important to choose a coating that will work to extend your tool’s life and aid in the removal of chips. A popular choice for this material bucket is Harvey Tool’s TiB2 coating.

Explore More TiB2 Tooling With Harvey Tool’s End Mills for Aluminum

What is Harvey Tool’s TiB2 Coating?

Harvey Tool’s TiB2 coating is a Titanium Diboride, ceramic-based coating that provides superb erosion resistance during machining. TiB2 is added to a tool by a method called Physical Vapor Deposition (PVD), which is conducted in a vacuum where particles are vaporized and applied onto a surface, forming thin layers of material onto the properly-prepped tool. This method enables the coating to be corrosion and tarnish resistant.

TiB2 Coating Specification chart

TiB2 is identified in Harvey Tool’s product catalog with a “-C8” following the sku number. It can be found offered in Harvey Tool’s lines of Variable Helix End Mills for Aluminum Alloys and Miniature High Performance Drills for Aluminum Alloys.

When Should a Machinist Use TiB2 Coating?

Chip Evacuation Concerns

TiB2 has an extremely low affinity to aluminum, which helps with the chip evacuation process. Simply, chips of a material are able to evacuate through chip valleys easier if they don’t have a high affinity to the coating being used. TiB2 coating does not chemically react with aluminum and magnesium, which allows for smoother chip evacuation, as the chips do not stick to the coating and create issues such as chip packing. This is a common machining mishap that can cause both part and tool damage, quickly derailing a machining operation. By using a coating that increases the lubricity of the tool, chips will not have a surface to stick to and will more smoothly evacuate from the flutes of the tool.

Large Production Runs

While an uncoated tool may work fine in some applications, not all applications can succeed without a tool coating. When working with large production runs where the tools need to hold up through the process of machining large numbers of parts, using a coating is always recommended because they extend the life of your tool.

When is TiB2 Coating Not Beneficial to My Application?

Extremely Abrasive Materials

During the PVD coating process, tools can reach a temperature in excess of 500° F, which can cause the toughness of the carbide to drop slightly. This process does not normally compromise the performance of the tool due to the coating being placed over the carbide. The coating then protects the slightly weakened edge and increases tool performance in recommended materials. Micro-fractures only start appearing when the tool is being run incredibly fast through highly abrasive materials, leading to a decrease in the life of the tool.

Extremely Soft Materials

The coating, while only a few microns thick at most, still provides an ever-so-slight rounded edge to the cutting edge of the tools it is placed on. It is important to take this into consideration, as using the sharpest tools possible when working with materials such as soft plastics is recommended. The sharpest edge possible decreases the likelihood of any “pushing” that might occur on the material and increases the likelihood of proper “shearing” when machining.

When Finish Is Vital

If your part’s finish is imperative to the final product, an uncoated tool may work better for your application. A coating, like stated above, creates a microscopic rounded surface to the cutting edge of the tool. When running tools at finishing speeds and feeds in materials like aluminum, a sharp edge can create the difference between a finished part that does – or does not – pass final inspection.