Alternative Practices

While vacuum sintering is the most widely used sintering practice for titanium, an alternative method uses purified argon for sintering powder-rolled titanium strip product. Argon is purified by passing it over titanium chips heated to 800 to 900 °C (1470 to 1650 °F).

The use of temperature cycling through the Ct-P transformation—880 °C (1620 °F) for unalloyed titanium—can promote densification; the effect is the most significant when heating from nto which lasts for —2 min.

Because large thermal lags exist in most vacuum furnaces, this technique is not practical for large production loads. In addition to normal sintering, a supplementary containerless HIP cycle can be used to improve density and mechanical properties (Ref 35, 39). Because the as-sintered density of P/M Ti-6Al-4V is 94 to 96% of theoretical, the porosity is not interconnecting, and densification can be achieved through the application of gas pressure and heat.

0 0

Post a comment