Preparation of Ti₃AlC₂ by mechanically activated sintering of 3Ti/Al/2C/0·2Sn

摘要

The mechanically activated sintering process was adapted to synthesize titanium aluminum carbide (Ti₃AlC₂) at low temperature. A mechanically induced self-propagation reaction occurred by mechanical alloying of 3Ti/Al/2C powder mixtures. In addition to powder products, a large amount of rigor granules with a size of 0.5 ∼ 10 mm were produced. Fine powders containing Ti₃AlC₂, Ti₂AlC and TiC were obtained. The granules composed of Ti₃AlC₂, Ti₂AlC and TiC. Adding Sn may remove Ti₂AlC and enhance the synthesis of Ti₃AlC₂. After Sn was added, the products only contained Ti₃AlC₂ and TiC. The Ti₃AlC₂ content of the powders and granules were 75 wt% and 88 wt%, respectively. The mechanically alloyed products were pressureless sintered at 900–1300°C for 2 h. Sintering of these products at 900 ∼ 1200°C yields samples containing over 95 wt% Ti₃AlC₂. The sintered powder compacts with high purity Ti₃AlC₂ had a fine organization. The lath Ti₃AlC₂ of the granules had a length of 10–20 μm.