Mechanical alloying of titanium

The mechanical alloying of titanium has previously been performed using fugitive process control agents (PCAs). In this work, calcium, magnesium, MgY or CrY are used as process control agents to balance between the cold welding and fracture phenomena, significantly increasing the process yield. The milled powder was then sintered using Spark Plasma Sintering (SPS) at low and high temperatures to achieve the best mechanical properties and a high quality microstructure. To understand the behavior of the PCAs, the same samples were heat treated at high temperatures. The use of a small quantity of calcium, as low as 0.250 wt%, permitted a high process yield, low oxygen content, good powder morphology and thermal stability. Due to the refined microstructure, the samples sintered at 950 °C exhibited mechanical properties similar to commercially pure Grade 4 titanium but with a much lower oxygen content.