ZCMIM post-sintering operation including:
Coining: Force sintered components to conform rigid mandrel, substrate to straighten, in order to guarantee desired MIM parts flatness and dimensions.This process will reduce spread dimensions for proper size features.
Machining: All common machining methods can apply to sintered MIM parts, like add threads, undercuts, grooves, ultra-tight tolerances, or special features.
Heat treating: Sintering process leave MIM parts in an annealed state, heat treatment can adjust high carbon ferrous alloys hardness and other properties. Precipitation hardened stainless steels need cycles of heat to optimize its mechanical properties. Sometimes, heat treatment are incorporated into sintering cooling cycle.
Hot deformation: Sintered parts will be heated and deformed by rapid forging stoke, in order to ensure proper size and density. Steel strength will increase form 500Mpa with sintering to 720Mpa with hot deformation.
Surface carburization: Carbon is an important element to attain high strength steel, utilize heating cycle with methane atmosphere will attain high surface hardness on MIM parts. Surface carburization results in dimensional precision loss, so we need to trade-off MIM parts surface hardness and dimensional accuracy.
Joining: MIM parts can be joined together by welding, brazing or adhesive techniques as other metallic components. MIM parts metal materials behave same as standard metals, laser welding is very effective for MIM stainless steels.
Surface treatments: MIM parts can be applied by various surface treatment as polishing, coating, painting, cleaning, anodizing, plating, sealing, and laser glazing. Electroplating is applied to improve MIM parts aesthetics and corrosion resistance. Nickel electroplate is perfect for instrumentation, firearm and magnetic components.
Hot Isostatic Press (HIP): MIM parts are typically 96-98% density after sintering process. HIP treatment will increase density to 100%. Sintered component will be loaded into a sealed chamber, then heat chamber and introduce argon gas. The heated gas create pressure to collapse internal porosity and compress MIM parts.