Powder Metallurgy Materials Powder Metallurgy Materials Machinery's Handbook, 31st Edition
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As precision-engineered materials, metal powders are available in a great variety for fabricating a wide range of products through the PM process. Generally, powder mixes for compacting are prepared from three powder types. The first type is admixed powder, in which elemental alloying powders (such as copper, nickel, graphite, and tin) are added to base element powders (such as iron or copper). The second type is partially alloyed powder, composed of two or more elements with alloying additives that are diffusion- bonded to the base powder during the powder manufacturing process. These powders produce a heterogeneous microstructure with good dimensional control and excellent as-sintered mechanical properties. The third type is prealloyed powder, which is atom- ized from alloyed furnace melts such that each powder particle has the same nominal composition throughout. Prealloyed powders yield homogeneous phase constituents in the microstructure. Conventional Materials.— For an overview of the scope of conventional materials, refer to Table 2, Table 3, Table 4, and Table 5 that follow. Table 2 lists basic materials for ferrous structural parts. Full specifications for a variety of ferrous PM structural materials are covered in ASTM Standard B783-19 and MPIF Standard 35. Table 2. PM Materials for Ferrous Structural Parts
Tensile Strength MPa
MPIF Designation Code a Composition
Density b g/cm 3
Material
Comments
F-0008 0.8C
6.9 6.9 6.7 6.7 7.1 7.1 7.1 7.1
370 390 410 590
Cost-effective
Carbon steel
F-0008-HT 0.8C FC-0208 FC-0208-HT 2Cu, 0.8C 2Cu, 0.8C FN-0205 2Ni, 0.5C FN-0205-HT 2Ni, 0.5C FL-4405 FL-4405-HT
Good sintered strength
Copper steel
390 Good heat-treated strength, impact energy
Nickel steel
1000
460
Good hardenability, consistency in heat treatment
0.85Mo, 0.5C 0.85Mo, 0.5C
Low-alloy steel
1100
FNL-4405
7.05
550
2Ni, 0.85Mo, 0.5C 2Ni, 0.85Mo, 0.5C
Hybrid low-alloy steel
Best heat-treated strength, impact energy
FNL-4405-HT
7.05 1170
FD-0205 1.75Ni, 1.5Cu, 0.5Mo, 0.5C 6.95 FD-0205-HT 1.75Ni, 1.5Cu, 0.5Mo, 0.5C 6.95 FLC-4608-HT 1.35Ni, 1.5Cu, 0.5Mo, 0.8C 7.0
540 900 690
Diffusion- alloyed steel
Best sintered strength
Sinter hardened steel
Hardenable in sintering
SS-316N2 SS-430N2 17Cr
17Cr, 12Ni, 2.5Mo
Stainless steel
6.57.1 410 410 Good corrosion resistance, appearance
a Reference: MPIF Standard 35, “Materials Standards for PM Structural Parts.” b Density is given as typical values.
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