Cold compaction study of Armstrong Process® Ti–6Al–4V powders

The Armstrong Process® developed by Cristal US, Inc./International Titanium Powder, is an innovative, low-cost technology for producing Ti and Ti alloy powders in a one-step, continuous process. In this work, Armstrong Ti–6Al–4V powders were characterized and the cold compaction behavior of the powders were investigated in detail. As-received as well as milled powders were uniaxially die-pressed at designated pressures up to 690 MPa to form disk samples with different aspect ratios. Samples with high aspect ratio exhibited non-uniform density along the pressing axis and the density distribution was consistent with the result predicted by finite element analysis. The model developed from the linear regression analysis on the experimental density data can be used to predict density of compacts with different aspect ratios. In the studied pressure range, an empirical powder compaction equation was applied to linearize the green density — pressure relationship. Cold compaction parameters were obtained for the as-received and milled Armstrong Ti–6Al–4V powders.

The die-pressing behavior of Ti-6Al-4V powders produced by the Armstrong Process® was studied in the case of disk shape compacts with 3 different aspect ratios. In the studied die-pressure range, an empirical powder compaction equation: ln1/(1−D)=AP+B [9], represents the relationship between green density (D) and die-pressure (P) relationship very well for both the as-received and milled Armstrong Ti-64 powders. Figure optionsDownload as PowerPoint slideHighlights
► Cold compaction behavior of Armstrong Ti–6Al–4V powders is studied.
► The green density variation in the powder compacts is evaluated.
► The green density of the powder compacts with different aspect ratios is predicted.
► An empirical powder compaction model fits the density–pressure data very well.