Looking for something other than mold release agents and coatings - which can sometimes be very tough on mold parts - to fight against wear and corrosion? The answer may lie in the In-Fusion ProcessT - a low-temperature, high-energy coating that is impregnated into tooling components, fusing the materials one atomic ion at a time.
According to Vincent Sciortino, vice president of Longmont, CO-based Ionic Fusion Corp. - inventors of the process - the company's zirconium nitride process impregnates the mold components and builds a ceramic matrix with one of the hardest, most lubricious materials known. "This leap in performance is due to the low coefficient of sliding friction, and the increased density achieved by our improved deposition process," he explains. "The hardness and strength rivals titanium, without the typical galling experienced with titanium nitride, making this process the best choice for all tool and die applications where high speed and quick release are critical. It also ensures that the material cannot peel, flake or separate like common plated and bonded coatings will."
This process addresses tooling components - not the mold as a whole. "Specifically, we look at all of the wear areas that move including the cavity and core, rotating cores, unscrewing molds, stack molds, etc., where the moldmakers want to add hardness and lubricity, which of course extends the life of the tool," Sciortino notes.
Company President Rod Ward adds that expensive tools and molds are not subjected to any deformation, change in dimensions or changes in grain structure due to the low operating temperatures of the process.
The In-Fusion process impregnates refractory metals into most substrates, such as injection and hot runner mold components, using ionic plasma deposition (IPD). "Specifically, the technology is used to ionically impregnate rigid or flexible substrate surfaces with a harder material," Sciortino explains. "These materials bond and strengthen the substrate material against wear. In many applications, the process will optimize for the substrate material and type of wear resistance required. Temperatures, pressures, kinetic energies of the substrate surface and the impinging ions will be adjusted to achieve the optimum results for the required application."
Sciortino explains how it works. "We fixture the components that are going to be treated inside a vacuum chamber. Inside the chamber is the target material (e.g., zirconium nitrite, or ZrN). We then pull a vacuum on our chamber and set the process parameters. What we mean by pulling a vacuum is that, at a certain time during the cycle, we are ready to produce a plasma within the confines of the chamber for the deposition of the zirconium into the parts."
Adds Ward, "The critical component here is that we create a plasma as opposed to just a vapor. A vapor is not pure; a plasma has purity. The plasma consists of ions, and our process uses high energy to drive the ions ballistically into the products to be treated. They are traveling in the realm of one-third the speed of light. So, after infusing the zirconium into the substrate, we then vent the chamber to atmosphere, open the chamber and out the parts come."
Furthermore, the process allows metals to be applied without change in dimensional stability at low temperatures of approximately 70xC (158xF) to insure that no change in metallography occurs to the bulk substrate. "The surface gains a conformal amorphous refractory metal, impregnated into the substrate, with a crystalline nitride as the finish layer," states John Petersen, the chief technology officer of the company. "The mechanical and electrical characteristics of these attributes can be changed utilizing different deposition parameters. Anti-oxidation, anti-wear (near diamond hardness), low friction and lubricity combat extremely corrosive, abrasive environments and high wear applications.
"As an example, tool steel surface hardness is increased from Rc 52 up to Rc 83 with zirconium nitride (ZrN) and a melt point of 2,980xC," Petersen continues. "Unlike plating, impregnated refractory metals will not peel, and the ionic fusion system is non-hazardous and not restricted by EPA regulations. As another very extreme example, we can impregnate titanium into paper."
The process also works on materials other than steels - it has proved successful with a number of alloys. "Most tooling alloys are in the Rc range of 30 to 52, very soft materials," Sciortino comments. "When we impregnate alloys with zirconium, they then have an Rc 85 hardness on the surface and much, much longer life with very high inherent lubricity. For example, moldmakers use beryllium for its heat dissipation properties and the fact that it can be cooled down quickly for faster cycle times, but with that said, it is a softer material that will wear quicker and is more prone to damage. Not only has the process increased the life of the tooling, but it also still maintains the desired heat dissipation properties."
As for what material is used for the ionic fusion process (see Sidebar), it is application-dependent, notes Ward, and depends upon customers' needs and requirements as well as metallurgy capabilities.
Moldmakers can utilize this process one of two ways: by sending in their mold components completely disassembled to the company or by purchasing a license to the technology and leasing the equipment. "Everything is digitally controlled, with a touch display," Ward explains. "We create the recipe here and upload it into the machine, so you can virtually put the parts in, close the door, and touch an icon on the touch screen. The door will open after the parts are finished." And as simple as that, moldmakers are ready to go.