SPS制备Ti-18Mo-xSi合金的高温氧化行为研究

High Temperature Oxidation-resistance Behavior of Ti-18Mo-xSi Alloy Prepared by SPS

采用高能球磨-放电等离子烧结技术制备了Ti-18Mo、Ti-18Mo-0.5Si、Ti-18Mo-1Si和Ti-18Mo-2Si4种合金,研究了Si含量对合金微观结构、相组成的影响及700和800℃空气中合金的氧化行为。结果表明:烧结合金中主要由Ti(Mo)固溶体组成,添加Si元素合金出现了Mo5Si3相。在700和800℃空气中分别氧化100 h后,合金表面主要有TiO2、Ti O、MoO2和MoO3相,添加Si元素的合金氧化后还出现了SiO2相。4种合金在700℃下的氧化增重明显小于800℃下的氧化增重,Ti-18Mo-0.5Si合金在700和800℃下平均氧化速率分别为0.09和0.10 g·(m2·h)-1,其抗氧化性明显优于其他合金。

Ti-18Mo, Ti-18Mo-0.5 Si, Ti-18 Mo-1 Si and Ti-18 Mo-2 Si alloys were prepared by high-energy ball mill and SPS. The effects of Si content on the oxidation-resistance behavior of Ti-18 Mo-x Si(x=0, 0.5, 1, 2) alloys at 700 and 800 °C in air were investigated by analyzing the microstructure, phase composition of sintered and oxidized alloys. The results show that the sintered alloys contain Ti(Mo) solid solution and the alloys with Si contain Mo5Si3 phase. After oxidation at 700 and 800 °C for 100 h, the main phases of alloys are TiO2, Ti O, MoO2 and MoO3, and the oxidized alloys with Si contain SiO2 phase. The oxidation resistance of Ti-18 Mo-x Si(x=0, 0.5, 1, 2) alloys at 700 °C is better than that at 800 °C. Average oxidation rate of Ti-18 Mo-0.5 Si alloy are 0.09 g·(m2·h)-1 and 0.10 g·(m2·h)-1 at 700 and 800 °C, respectively. The Ti-18 Mo-0.5 Si alloy is superior to other alloys in oxidation resistance.