通孔构型Ti6Al4V/Ti_(2)AlC-TiAl基叠层复合板材的组织和性能

Microstructure and Properties of Ti6Al4V/Ti_(2)AlC-TiAl Based Laminated Composite Sheet with Through-hole Structure Design

将Ti-Al-TiC混合粉末和通孔构型TC4钛合金箔(Ti6Al4V)依次叠放装入模具,采用放电等离子烧结技术(SPS)制备了珍珠层结构Ti6Al4V/Ti_(2)AlC-TiAl基叠层复合板材。采用XRD、SEM、EBSD等测试手段分析相组成及微观结构,测试其室温力学性能,研究其强韧化及断裂机理。结果表明,Ti_(2)AlC理论生成量为10%(质量分数)时,复合板材在垂直于叠层方向弯曲强度和断裂韧性达到最大值,分别为645.77 MPa和25.06 MPa·m^(1/2)。通孔构型TC4钛合金强韧层设计改变了裂纹扩展路径,使裂纹扩展驱动力不断被削弱,同时第二相Ti_(2)AlC对裂纹扩展也产生阻碍作用,从而提高了TiAl基叠层复合板材的综合力学性能。

Inspired by nature,Ti6Al4V/Ti_(2)AlC-TiAl based laminated composite sheets with nacre structure were prepared by spark plasma sintering(SPS)overlaying Ti-Al-TiC mixed powders and TC4 titanium alloy foils(Ti6Al4V)with through-holes each other,and the phase composition and microstructure were analyzed by XRD,SEM,EBSD,and the room temperature mechanical properties were measured.The strengthening-toughening mechanism and fracture mechanism were investigated.The results showed that when the theoretical content of Ti_(2)AlC was 10wt%,the flexural strength and fracture toughness of the composite sheet in the direction perpendicular to the laminate reached the maximum values,which were 645.77 MPa and 25.06 MPa·m^(1/2),respectively.The structured design of the TC4 titanium alloy layers with through-holes changed the crack propagation path,resulting in the driving force of crack propagation was constantly weakened.At the same time,the formation of Ti_(2)AlC phases also had impact on the crack propagation,and improving the comprehensive mechanical properties of TiAl-based laminated composite sheets.