放电等离子烧结制备TiAl合金组织和性能

Microstructure and Mechanical Properties of TiAl Alloy Prepared by Spark Plasma Sintering

以气雾化工艺制备的Ti43.5Al5Nb1V1Y(at.%)预合金粉末为原料,采用放电等离子烧结工艺成功制备细晶TiAl合金,研究不同烧结温度(1200~1300℃)对组织和力学性能的影响。通过采用OM,XRD,SEM等方法对烧结试样进行微结构表征,在力学试验机进行室温压缩试验。研究发现,烧结后试样主要有γ-TiAl、α2-Ti3Al和少量的YAl2相构成。烧结温度为1200℃时致密度高,其压缩断裂强度为2098.5 MPa;温度高于1200℃时,致密度未发生明显的变化,断裂强度和塑性变形量有所增加;烧结温度为1250℃时,细小的双态组织显示出较好的力学性能。

The Ti43.5Al5Nb1V1Y(at.%)prealloyed powder prepared by the gas atomization process was used as the raw material,and the fine grained TiAl alloy was successfully prepared by the spark plasma sintering process.The effects of different sintering temperatures(1,200~1,300℃)on the microstructure and mechanical properties were investigated.The microstructure of the sintered sample was characterized by OM,XRD,SEM,etc.,and the room temperature compression test was carried out in a mechanical testing machine.It is found that the sintered samples are mainly composed ofγ-TiAl,α2-Ti3Al and a small amount of YAl2 phase.When the sintering temperature is 1,200℃,the density is high,and the compressive breaking strength is 2,098.5 MPa.When the temperature is higher than 1,200℃,the density does not change significantly,and the breaking strength and plastic deformation amount increase.When the sintering temperature is 1,250℃,the fine two-state structure shows better mechanical properties.