Powder Metallurgy PM Method Make fine metal powders

Powder Metallurgy (P/M) Method: • Make fine metal powders and sort • Mix powders to get “alloy” • Iron alloys most common, also Bronze • Compaction • Powder is pressed into a “green compact” • 20, 000 -100, 000 psi pressure • Still very porous, ~70% density • May be done cold or warm (higher density) • Sintering • Controlled atmosphere: no oxygen • Heat to. 75*Tmelt • Particles bind together • Part shrinks in size • Density increases, up to 95% • Strength ~=~ Density P/M net-shape gears are common, save machining time P/M (vs. Casting): • Mass produce small steel parts, net-shape • Less waste • Unusual “alloys” • Range of densities, porosity (adv or disadv) • Less energy use • But: Smaller parts and less complexity (2. 5 D) oee. nrcan. gc. ca

Powder Metallurgy Slightly porous appearance is common Range of particle sizes www. buau. com. au www. parmaco. com

Cermet cutting inserts for lathe Powder Metallurgy: Cermet cutting tools (Ceramic-Metal composite) www. kyocera-yashica. com. br Microstructure: ceramic particles in metal matrix Cermet-tipped saw blade for long life www. moldmakingtechnology. com www. toolbarn. com

Metal filters Powder Metallurgy: Porous Metals Oil-impregnated Porous Bronze Bearings nic. sav. sk www. ondrives. com www. hd-bearing. com

Powder Metallurgy: Connecting Rods www. dps-performance. com Forged on left; P/M on right

Powdered Metal Transmission Gear www. chipm. com • Warm compaction method with 1650 -ton press • Teeth are molded net shape: No machining • UTS = 155, 000 psi • 30% cost savings over the original forged part

Powdered Metal Turbine blade-disk (“blisk”): 1 piece! www. ml. afrl. af. mil

Conventional Forging vs. Forging of Powdered Metal blank (2 nd op) De. Garmo

References De. Garmo: E. P. De. Garmo et al, Materials and Processes in Manufacturing, Wiley, 2003.