Diamond is the hardest material known and the most resistant to abrasion, making it – including synthetic diamonds such as polycrystalline diamond (PCD) – ideal for cutting tools. PCD tools notably offer longer cutting life, can operate at higher cutting speeds, and have exceptional performance processing non-ferrous materials such as aluminum and composites.
Diamond can be synthesized by subjecting carbon’s hexagonal phase to extreme pressures and temperatures by using large hydraulic presses. Using a catalyst eases conversion of graphite to a harder cubic phase.
PCD producers mix diamond powders and place them on a cemented carbide substrate disc and encase that in a protective metal canister. The capsule is then loaded into the high pressure, high temperature (HPHT) system for 30 mins. to 120 mins.
Manufacturing application demands determine the choice of PCD tooling cutting tool material. The important requirements to consider are abrasion resistance, toughness, strength, and workpiece finish. The ability to grind, EDM materials, and cutting edge quality also influence grade choice to achieve the best abrasion resistance and toughness.
Putting PCD to work
Creating and selecting the right PCD grade is only the beginning. Making an accurate, effective PCD cutting tool requires expertise, high-level engineering, and innovation.
“Design and application engineering are critical to creating PCD cutting tools,” says Charlie Novak Jr., Arch® Cutting Tools’ business development manager/coordinator Arch Specials. “Focusing on providing an overall solution and working on the process instead of focusing on simply creating a single tool is important.
“It’s even better if that can be accomplished with no outsourcing, so a single tooling provider can deliver a total solution to a manufacturer, from materials to finished tooling, and then support that solution with professional services.”
Novak notes that Arch offers “innovative design and application engineering with a dedicated team of design engineers operating within our proprietary process capable of responding to today’s accelerated demands.”
Arch Cutting Tools process delivers total tool tolerances as tight as 0.003mm, and inspection reports are available for every tool produced.
Arch Specials will re-tip its tools with turn-around within two weeks to maintain productivity for its customers. Additionally, Novak adds, Arch Specials will re-tip tools from competitors to support its customers.
The secret to the best tooling solutions lies in the process behind the design and application engineering.
“In reality, our customers are buying a hole – sort of the middle of the doughnut,” says Charlie Novak Sr., general manager – Arch Mentor (Ohio). “What they need is a precise hole in their product and they’re relying on our tool to create that hole; and it has to be right the first time and right every time.”
Although cutting tools represent a relatively small percentage of the total cost to manufacture a specific product, the cost of lost production because of the tool’s failure to perform properly can be substantial. PCD cutting tools can last up to 25x longer than an equivalent carbide tool.
Correct cutting parameters are key to realizing the true value of PCD compared to other cutting tools, adds Novak Jr.
“An operation can generally machine much faster. At higher speeds with increased chip load, the greatest increase is with speed. PCD maintains a sharper edge and has a lower coefficient of friction. Those characteristics, coupled with the proper speeds and feeds, will result in better surface finish and increased throughput.”
PCD cutting tools, created through a rigorous design and application engineering process, deliver longer tool life – requiring less adjustment throughout the life of the tooling, with more throughput, to capture all available cost savings for manufacturers without compromising quality or productivity.