Powders for metal injection molding

Powder Injection Molding of Metal and Ceramic Parts

“…Currently, there is a tendency to use submicron and nanoparticles, since a better packing density can be achieved, their activation energy is higher and their sintering temperature is lower (Shearwood et al, 2005). Nevertheless, care must be taken when handling nano powders since they can be explosive or can easily oxidize; therefore most of the time powder metallurgy utilizes particles in the 1 to 45 m range (Hartwig et al, 1998). In particular, for metal injection molding the mean particle size ranges from 5 to 15 m (Krug et al, 2002).…”

“…The most commonly used powders in today's MIM production are carbonyl powders. Simple mixtures of iron and nickel carbonyl powders are the basis of powder mixtures for metal injection molding; other metals included in these mixtures include heat treatable steels and stainless steels (Hartwig et al, 1998).…”

“…Gas atomized powders leads to mostly spherical particles ( Fig. 6) but the yield of particles below 45 mm is limited (Hartwig et al, 1998).…”

The influence of particle size distribution on the properties of metal-injection-moulded 17-4 PH stainless steel

“…The latter result is expected, since smaller particles have a larger specific surface area, necessitating a larger amount of binder which therefore increases the shrinkage level during sintering (Hartwig et al, 1998). PS-15-60 and PS-5-60 specimens do not show a significant difference in their shrinkage levels; however, the PS-5-60 specimen indicates a slightly lower average shrinkage level and this can be attributed to the presence of an oxidation film on the surface of the particles that delays sintering rate and hence shrinkage.…”

Interaction of plastic zone, pores, and stress ratio with fatigue crack growth of sintered stainless steel

“…The selection between P/M and MIM depends on the complexity of required components. Mass production of small and complex components is highly suitable for MIM [4,5]. Although the MIM is suitable for mass production of small and complex components; the presence of pores within MIM parts may cause the reduction in strength and ductility [5][6][7].…”