Influence of Sintering Temperature on Mechanical Properties of Ti-6Al-4V Compacts by Metal Injection Molding

Abstract

Titanium and titanium alloys have low density, high strength, excellent corrosion resistance in many media and are known to be biocompatible. This combination of properties makes titanium and its alloys an excellent choice for the applications, such as watch parts, medical devices, dental parts and sports goods. However, in the respect of fabricating complicated shaped parts, low machinability may be a barrier to practical uses. Therefore, it is considered to be very available that metal injection molding(MIM) process is applied to fabricate titanium alloy parts[1-2]. Nevertheless, injection molding of titanium and its alloys presents a real challenge to the processor due to its reactivity. Titanium not only has a strong affinity to oxygen, but also tends to react readily with carbon, nitrogen or hydrogen from the furnace atmosphere. Therefore, contamination by interstitial light elements such as oxygen and carbon is a serious problem because they have much influence on the mechanical properties of titanium alloys[3-5]. So it is necessary to control debinding and sintering conditions. In this paper, preparation of Ti-6Al-4V compacts was performed by MIM process. To reduce the contamination, the debound compacts were sintered at moderate temperature range from 1170°C to 1320°C and high vacuum (10-3Pa). On these conditions, the mechanical properties and relative density of sintered compacts were investigated.