射出成形によるFe-Ni合金の焼結過程における炭素の役割 Role of Carbon during Sintering Process in Fe-Ni Alloy Compacts Made by Injection Molding
On Fe-4mass%Ni alloy compacts shaped by metal injection molding, the relationship between the C and O contents of debound compacts and those of sintered compacts was examined by introducing a parameter, ΔC<SUB>d</SUB>≡C<SUB>d</SUB>-aO<SUB>d</SUB>, which represents the stoichiometric ratio of C and O contents(C<SUB>d</SUB> and O<SUB>d</SUB>, respectively) of the debound wmpacts. Specimens were made of carbonyl Fe(reduced grade; 5.0μm, 0.05mass%C, 0.2mass%O)and carbonyl Ni(2.0μm)and additional C powder. The amount of additional C powder was 0 to O.8g per 100g of Fe-4mass%Ni mixed powder. The specimens were debound in air at temperatures ranging from 503 to 553K for 7.2ks, and were sintered in a reduced pressure of 1Pa at 1523K for 7.2ks. The obtained results were as follows. The reaction M<SUB>x</SUB>O+C→xM+CO(M=Fe, Ni)was dominant for reducing metal oxides during sintering process. In the case of ΔC<SUB>d</SUB>>-0.2, the relative densities of sintered compacts were about 95%, regardless of the amount of additonal carbon. Theadditional carbon did not improve the densification of sintered compacts.
粉体および粉末冶金 43(5), 656-662, 1996-05-15
Japan Society of Powder and Powder Metallurgy