Microstructure characteristics and mechanical properties of TiB/Ti-1.5Fe-2.25Mo composites synthesized in situ using SPS process

TiB/Ti-1.5Fe-2.25Mo composites were synthesized in situ using the spark plasma sintering （SPS） method at temperatures of 850-1150 °C. The effect of the sintering temperature on microstructure and mechanical properties of the composites was investigated. The results indicate that the aspect ratio of the in situ synthesized TiB whiskers in Ti alloy matrix decreases rapidly with an increase in sintering temperature. However, both the relative density of the sintered specimens and the volume content of TiB whiskers in composites increase with increasing sintering temperature. Thus, the bending strength of the composites synthesized using SPS process increases slowly with increasing the sintering temperature from 850 to 1150 °C. TiB/Ti-1.5Fe-2.25Mo composite synthesized at 1150 °C using SPS method exhibits the highest bending strength of 1596 MPa due to the formation of fine TiB whiskers in Ti alloy matrix and the dense microstructure of the composite.

放电等离子烧结制备高铌TiAl合金

以Ti-45Al-8.5Nb-0.2B-0.2W-0.1Y合金粉末为原料,采用放电等离子烧结工艺制备了高铌TiAl合金。结果表明,当烧结温度高于1000℃时,可制备出致密度高、组织均匀的高铌TiAl合金;烧结温度对合金的显微组织影响显著,通过改变烧结温度可得到具有近γ(NG)、双态(DP)、近片层(NL)、全片层(FL)4种典型组织的高铌TiAl合金;合金的室温力学性能与显微组织密切相关,当烧结温度为1100℃时,所制备合金显微组织为细小双态组织,其抗拉强度为1024MPa,延伸率为1.16%,显示出较好的室温力学性能。