Metal injection molding of Fe54Ni29Co17 alloy from blends and pre-alloyed powders
A comparison study
Metallspritzgießen der Legierung Fe54Ni29Co17 aus Gemischen und vorlegierten Pulvern: eine Vergleichsstudie
Due to their low thermal expansion coefficient, Fe54Ni29Co17 alloys are of interest for many applications as in the electronic or automotive industries. Processing via MIM (Metal Injection Molding) allows cost-effective large scale production of parts with complex shapes with a very good accuracy and surface finish. There is today on the market a number of commercially available feedstock but as the trend goes to the production of smaller and more complex MIM parts new feedstock are needed to still meet the shape accuracy and surface finish required on those tinier pieces. In this study Fe54Ni29Co17 parts were prepared by MIM starting from feedstock made of blended iron, nickel and cobalt powders, iron with co-precipitated 37Co63Ni and a fully pre-alloyed powder. The feedstock composition was optimized according to the different metal powder mixes used. The sintering parameters were evaluated accordingly. Shrinkage, density, thermal expansion coefficient, carbon content, microstructure and distribution of the metal elements of the sintered parts were studied as a function of feedstock composition, sintering temperature and sintering duration. For blends and co-precipitated 37Co63Ni, densities close to the theoretical density were achieved. The surface roughness of the sintered pieces was close to surface of polished parts. All prepared MIM parts showed no cracks and a very good contour accuracy.