The investigation of die-pressing and sintering behavior of ITP CP-Ti and Ti-6Al-4V powders

This paper investigated the die-pressing and sintering behavior of ITP CP-Ti and Ti-6Al-4V powders produced by the Armstrong Process®. The ITP powders have an irregular coral like, dendritic morphology, with a dendrite size of approximately 2–5 μm. As-received as well as milled powders were uniaxially pressed at designated pressures up to 690 MPa to form disk samples with different aspect ratios. In the studied pressure range, an empirical powder compaction equation was applied to linearize the green density – pressure relationship, and powder compaction parameters were obtained. The ITP Ti-6Al-4V powder exhibited a significantly higher sinterability than the CP-Ti powder. This was explained to be due to the higher diffusivity of V in β-Ti at the sintering temperature. The Ti-6Al-4V samples with a green density of 71.0% increased to 99.6% after sintering at 1300 °C for 1 h. An ex-situ technique was used to track the powder morphology change before and after sintering.

► Die-pressing behavior of ITP CP-Ti and Ti-6Al-4V powders is studied.
► An empirical powder compaction model fits the density-pressure data very well.
► The Ti-64 powder exhibited much higher sinterability than the CP-Ti powder.
► The sinterability difference is attributed to the specific surface area and V diffusion.