(1. 西北工业大学 凝固技术国家重点实验室，西安 710072；
2. 中国航空工业集团公司 北京航空材料研究院，北京 100095；
3. 西部超导材料科技有限公司，西安 710021)
摘 要: 研究TC21合金经β相区固溶并慢速冷却后的片层组织特征(晶界α层厚度、α片层宽度、α集束尺寸)及断裂韧度随冷却速率的变化规律，探讨片层组织特征与断裂韧度的关系。结果表明：随着冷却速率的增大，TC21合金α片层集束、α片层厚度及晶界α层宽度均减小。在本文实验测试尺度范围内，α片层宽度、α片层集束尺寸及晶界α层厚度的增大均可提高合金的断裂韧性。
关键字: TC21钛合金；片层组织特征；断裂韧度
fracture toughness of TC21 alloy
（1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
2. Beijing Institute of Aeronautical Materials, Aviation Industry Corporation of China, Beijing 100095, China;
3. Western Superconducting Technologies Co., Ltd., Xi’an 710021, China）
Abstract:In order to analyze the relationship between lamellar microstructure feature (thickness of α laths, width of α lath at grain boundary and α colony size) and fracture toughness, the microstructures and fracture toughness of TC21 alloy cooled from β phase field with different slow rates were investigated. The results show that α colony size together with α laths thickness and width of α lath at grain boundary is decreased with increasing cooling rates, leading to the decrease of fracture toughness. It is positive for fracture toughness to decrease width of α lath at grain boundary, α laths thickness and α colony size.
Key words: TC21 alloy; lamellar microstructure feature; fracture toughness
