材料期刊网

Ti(3)SiC(2) shows a unique combination of the properties of both metals and ceramics. However, its stiffness and strength lose rapidly above 1050 degrees C, which is the main obstacle for the high-temperature application of this material. To improve the high-temperature mechanical properties of Ti(3)SiC(2), Zr, Hf, or Nb were used as dopants in Ti(3)(SiAl)C(2). At room temperature, the Zr-, Hf-, or Nb-doped Ti(3)(SiAl)C(2) ceramics have comparable stiffness, hardness, strength, and fracture toughness with those of Ti(3)(SiAl)C(2). At high temperatures, however, a significant improvement in stiffness and strength has been achieved for (Ti(1-x)T(x))(3)(SiAl)C(2) (T=Zr, Hf, or Nb). (Ti(1-x)T(x))(3)(SiAl)C(2) can retain high degrees of stiffness and strength up to 1200 degrees C, which is 150 degrees C higher than those for Ti(3)(SiAl)C(2).