SPS烧结温度对Ti-45Al-8Nb合金组织及力学性能的影响  

Effect of SPS Temperatures on Microstructure and Mechanical Properties of Ti-45Al-8Nb Alloy

作　　者：董多[1,2] 苏勇君 朱冬冬[1] 周兆忠[1] 倪成员[1] 贺庆[1] Dong Duo;Su Yongjun;Zhu Dongdong;Zhou Zhaozhong;Ni Chengyuan;He Qing(Key Laboratory of Air-driven Equipment Technology of Zhejiang Province,Quzhou University,Quzhou 324000,China;State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China;Lishui University,Lishui 323000,China)

机构地区：[1]衢州学院浙江省空气动力装备技术重点实验室,浙江衢州324000 [2]北京科技大学新金属材料国家重点实验室,北京100083 [3]丽水学院,浙江丽水323000

出　　处：《稀有金属材料与工程》2019年第12期4101-4105,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金（51501100,51801112）;浙江省自然科学基金（Y18E010014）

摘　　要：以雾化法制备的Ti-45Al-8Nb(at%)预合金粉末为原料,采用放电等离子烧结工艺技术(SPS)制备了Ti-45Al-8Nb合金,研究了不同烧结温度对合金显微组织及力学性能的影响规律。结果表明,在烧结温度范围内(1250、1275、1300℃),合金均为全片层组织,并具有高抗压强度和压缩率。随着烧结温度的提高,合金中γ相含量升高,α2相含量下降。1250℃放电等离子烧结时,合金中并未出现B2相,随着烧结温度的升高,合金中的B2相主要由晶界析出,并呈增多的趋势。分析表明,主要是由于放电等离子烧结过程中使得粉末间产生局部高温形成液相,其后的快速凝固导致高温β相来不及转变而形成的B2相残留。合金总体表现出随着烧结温度的升高,合金的强度和塑性性能下降的趋势。SPS烧结温度为1250℃时,抗压强度和压缩率最佳,分别为2084.20 MPa和33.10%。合金SPS烧结温度为1250和1275℃时,断裂模式主要为沿片层断裂和穿片层断裂混合方式。SPS烧结温度为1300℃时,断裂则主要以沿片层断裂为主。TiAl alloys with nominal composition of Ti-45 Al-8 Nb(at%) were prepared by spark plasma sintering(SPS) process. The effect of sintering temperatures on microstructure and mechanical properties of Ti-45 Al-8 Nb alloy was studied. The results show that the microstructures of Ti-45 Al-8 Nb alloy sintered at different temperatures all exhibit full lamellae structure. With the increasing of sintering temperature, the amount of γ phase in the alloy increases and that of α2 phase decreases. There is no B2 phase when sintered at 1250 °C. As the sintering temperature increases, the B2 phase precipitates at the grain boundary and the amount of B2 phase increases. The main reason is that the alloy may melt at local areas with the increasing of sintering temperature;the β phase would order into B2 phase at high cooling rates. The tensile strength and compression ratio decrease with the sintering temperature increasing from 1250 °C to 1300 °C. The maximum tensile strength and compression ratio reach 2084.20 MPa and 33.10% at 1250 °C, respectively.

关 键 词：放电等离子烧结 Ti-45Al-8Nb 预合金粉末 组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]