The influence of iron powder size on pore formation, densification and homogenization during blended elemental sintering of Ti-2.5Fe

In this study it was determined that the addition of Fe to a Ti powder mixture results in pore formation either through the slow, solid state diffusion of Fe below the eutectic point (1085 °C), or as a result of Fe rich liquid formation above 1085 °C. The size of the pores scales proportionally with the size of the Fe particles used. Subsequent densification at 1200 °C increased with a decrease in Fe particle size. The rate of Fe in-situ alloying and microstructural homogenization during sintering was determined using a newly developed differential scanning calorimeter (DSC) method. The rate of homogenization increased with a decrease in Fe particle size. The use of sub 10 μm Fe powder resulted in improved densification compared to pure Ti and leads to complete homogenization during heating to 1200 °C.