High-Temperature Compressive Properties of TiC-Added Mo-Si-B Alloys
High-Temperature Compressive Properties of TiC-Added Mo-Si-B Alloys
复制标题
添加 TiC 的 Mo-Si-B 合金的高温压缩性能
作者：
K. Yoshimi;J. Nakamura;Daiki Kanekon;Shiho Yamamoto;K. Maruyama;H. Katsui;T. Goto
添加TiC的两种Mo-Si-B合金的高温压缩性能，名义成分为Mo-5Si-10 B-7.5 TiC（70 Mo合金）和Mo-6.7 Si-13.3 B-7.5 TiC（65 Mo合金）（at.%）考察合金由Mo固溶体（Moss）、Mo 5SiB 2、（Mo，Ti）C和（Mo，Ti）2C四个组成相组成。70 Mo和65 Mo合金的初生相分别为Moss和T2。65 Mo合金的压缩变形能力即使在1600°C下也受到显著限制，这是因为细长的、粗的初生T2相，而70 Mo合金在1000-1600°C的测试温度范围内具有良好的压缩变形能力和高强度;峰值应力在1000°C下为1800 MPa，在1200°C下为1230 MPa，在1600°C下为350 MPa。在1200°C和1200°C以上，峰值应力值是Mo-6.7Si-7.9B、Ti-Zr-Mo和Mo-Hf-C合金的两倍以上。在低于韧脆转变温度T2的温度下，70 Mo合金中的塑性应变不仅由Moss的塑性变形产生，而且由（Mo，Ti）C和（Mo，Ti）2C的塑性变形产生。研究表明，（Mo，Ti）C和（Mo，Ti）2C对添加TiC的Mo-Si-B合金的高温强度和变形性能起着重要的决定作用。
High-temperature compressive properties of two TiC-added Mo-Si-B alloys with nominal compositions of Mo-5Si-10B-7.5TiC (70Mo alloy) and Mo-6.7Si-13.3B-7.5TiC (65Mo alloy) (at.%) were investigated. The alloys were composed of four constituent phases: Mo solid solution (Moss), Mo5SiB2, (Mo,Ti)C, and (Mo,Ti)2C. The primary phases of the 70Mo and 65Mo alloys were Moss and T2, respectively. The compressive deformability of the 65Mo alloy was significantly limited even at 1600°C because of the elongated, coarse primary T2 phase, whereas the 70Mo alloy had good compressive deformability and a high strength in the test-temperature range of 1000–1600°C; the peak stresses were 1800 MPa at 1000°C, 1230 MPa at 1200°C, and 350 MPa at 1600°C. At and above 1200°C, the peak stress values were more than double those of Mo-6.7Si-7.9B, Ti-Zr-Mo, and Mo-Hf-C alloys. The plastic strain in the 70Mo alloy at temperatures lower than the ductile–brittle transition temperature of T2 was generated by plastic deformation of not only Moss but also of (Mo,Ti)C and (Mo,Ti)2C. This work indicates that (Mo,Ti)C and (Mo,Ti)2C play an important role in determining the high-temperature strength and deformation properties of TiC-added Mo-Si-B alloys.