Allomet - About TCHPs

New Paradigms In Powdered Metals

As the first fundamentally new material technology since tungsten carbide was developed over 70 years ago, Allomet’s products deliver the elusive combination of property extremes and performance that state-of-the-art materials cannot.

Since the beginning of metallurgy, the properties of materials and composites have been constrained by solubility limits, diffusion coefficients, and compatibility of physical and chemical constituent properties. Alloys average the mechanical properties of the constituent metals and the property extremes are lost. To escape these limits of nature, ingenious — now conventional — ways of combining strength, toughness, and wear resistance have been devised using various coatings and laminations. In about 80% of carbide tool applications, tungsten carbide wear performance is improved via external coatings that are only about 1/5 to 1/4 the thickness of a human hair. Such tools are systematically discarded after only about 10% of their wear tolerance has been used.

Tough-Coated Hard Powders (TCHP), or EternAloy® grade, patented by Allomet-USA (U.S. Patent No. 6,372,346 et al.), are extremely hard refractory particles CVD coated with nanolayers of (1) WC or TaC and (2) Co or Ni binder. TCHP enables us to nanoengineer material properties. Encapsulating fine particles having one set of desirable properties with grain boundary modifiers having other properties provides heretofore-uncombinable material-property combinations. This allows the materials engineer to “alloy” materials previously “un-alloyable.” With over 30 candidate core materials, thousands of EternAloy® grade combinations are practically possible. EternAloy® grade allows us to engineer almost any properties we can imagine (e.g., light weight, low coefficient of friction, high or low thermal conductivity, lubricity, …) in sintered materials, and the applications seem limitless.

This merging of multiple property extremes into all-in-one “designer particles” enables an unprecedented near-atomic scale integration of thermodynamically incompatible materials and properties so that they operate simultaneously and seamlessly at the finest possible scale at working surfaces and cutting edges of tools.

The same principle has been proven effective in thermally-applied coatings. The TCHP nanoencapsulated “building block” TCHP particle contains all the essential elements (of hardness + wear resistance + toughness + binder metal + other designer properties) and gives the materials engineer thousands of new material grades with engineered properties simultaneously optimized at the nano-, micro-, macro- and functional levels.

Consolidation of TCHP creates an engineered highly homogeneous cellular structure whose contiguous tough WC-Co “shells” each contain a wear-resistant core (e.g., TiN). In TCHPs, the tough coatings chemically bond throughout the tool, combining the strength, heat resistance, and toughness of cemented carbides with the chemical and abrasion wear resistance of harder core particle materials. As wear progresses, new wear-resistant material continuously replaces the working surfaces and edges of the tool until its geometry reaches its maximum limits. TCHP tools are then reusable many times by relapping or electro-discharge machining (EDM).

EternAloy® grade also has major applications in aerospace, automotive, industrial, mining, petroleum and natural gas drilling, and components because of its light weight and unique properties.