热暴露对TC11/Ti-22Al-25Nb双合金盘力学性能的影响  

Effect of Thermal Exposure on Mechanical Properties in Welding Seam of TC11/Ti-22Al-25Nb Dual Alloy

作　　者：申景园 姚泽坤[1] 宁永权[1] 邹书亮 Shen Jingyuan;Yao Zekun;Ning Yongquan;Zou Shuliang(Northwestern Polytechnical University,Xi＇an 710072,China)

机构地区：[1]西北工业大学,陕西西安710072

出　　处：《稀有金属材料与工程》2018年第8期2511-2517,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51175431)

摘　　要：对电子束焊+近等温成形的TC11/Ti-22Al-25Nb双合金模拟盘在热暴露后进行拉伸、持久试验,并通过SEM和TEM观察断口形貌及组织。结果表明:热暴露后的试样在室温拉伸时,均断裂在焊缝位置。经550℃热暴露后室温拉伸试样的断裂属于延性断裂,600℃热暴露后室温拉伸试样的断裂属于脆性解理断裂,裂纹源均起始于试样的表面。随着热暴露温度的升高和时间的延长,室温拉伸强度总体提高,塑性下降,持久时间也降低,元素在焊接连接区域的分布更加均匀,成分曲线表现得更加平缓,但在Ti-22Al-25Nb侧检测出较高含量的O元素,说明该侧合金易被氧化。Thermal exposure of electron beam welded ＋ near isothermally forged TCll/Ti-22A1-25Nb dual alloy simulation disc was conducted at 550℃ and 600℃ for 300 h and 500 h. Then the microstructures and fracture morphologies at the fracture position of the samples were investigated through tensile and stress-rupture experiments and observed by SEM and TEM. The results indicate that during the tension process at room temperature, the thermally exposed sample always fractures in the weld. After 550℃ thermal exposure, the fracture of tensile samples is ductile while the tensile samples are of brittle cleavage fracture when experiencing 600℃ thermal exposure, and cracks always originate in surface of the sample. As the thermal exposure temperature rises and the time extends, there is an overall improvement in room temperature tensile strength, the ductility decreases, the lasting time shortens, and the elements of the welding connection area are distributed more uniformly, and the composition curve becomes smoother. However, much O element has been found in the Ti-22A1-25Nb zone, indicating this alloy can be oxidized easily.

关 键 词：热暴露 TC11/Ti-22Al-25Nb双合金 力学性能 组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]