Processing of Titanium Powder into Consolidated Parts & Sheet

The processing of titanium powder has been presumed to have potential to reduce the cost of final parts. The non-melt routes to efficient powder processing require consistent flow, adequate tap density and minimal pick-up of interstitial contaminants. The powder produced by the continuous sodium reduction of titanium tetrachloride has a coral-like morphology and low tap density. In order to achieve the potential of low cost parts, the powder will need to be modified to match the optimum feed conditions of the particular processing technique. The approaches to control interstitial pick-up will be discussed in the context of manufacturing technology: contribution of raw materials (10%), passivation (60%) and densification (30%). A comparison of densification with a change of milling fluid media (argon to water will be made with the unexpected decrease in oxygen pick-up when using water). Powder spheroidization via gas atomization of Armstrong Process® powder will be discussed. The product forms where the advantages of using powder can be exploited have to be carefully selected. Sheet is one such form: the results of using titanium powder to directly make titanium sheet will be presented.

Investigation of Pressing and Sintering Processes of CP-Ti Powder Made by Armstrong Process

This work used in-situ and ex-situ techniques to investigate the pressing and sintering processes of commercially pure (CP) Ti powder made by the Armstrong process. The objective is to simulate the actual manufacturing process of near net shape Ti components. Ti powders were uniaxially pre-pressed at designated pressures up to 100 ksi to form disk samples with different theoretical densities. Compression tests were performed in an SEM at different temperatures to obtain the mechanical properties and deformation behavior of these samples. Ex-situ technique was used to track the powder deformation process of disk samples from low pressure to high pressure. In-situ sintering was also performed in an SEM to record the morphology change of the porosities on the sample surface during the sintering process. The results will provide valuable information for optimizing the manufacturing process of high-density near net shape Ti components.