(1. 甘肃工业大学 材料科学与工程学院, 兰州 730050;
2. 西安工业学院 材料工程系, 西安 710032)
摘 要: 工业纯钛经喷丸、滚压强化后,疲劳强度得到不同程度的提高。逐层TEM亚结构对比分析结果表明:工业纯钛疲劳强度的提高和强化层组织中孪晶的形成有关;工业纯钛疲劳前后组织中主要是位错数量的变化,而强化试样疲劳前后组织结构既有位错、孪晶数量的变化,又有孪晶晶界、孪晶孪晶之间的交互作用;喷丸较滚压强化效果显著的部分原因是表层形成了准孪晶栅栏。
关键字: 钛; 孪晶; 疲劳; 表面强化
microstructure of commercial purity titanium
(1. College of Materials Science & Engineering,
Gansu University of Technology, Lanzhou 730050, P.R.China;
2. Department of Materials Engineering,
Xi′an Institute of Technology, Xi′an 710032, P.R.China)
Abstract: The fatigue strength of commercial purity titanium was improved through shot-peening or cold-rolling treatment. By means of TEM methods to analyze the various layer substructures, the following results were obtained: (1) The improvement of fatigue strength of commercial purity titanium is related to the formation of twins in strengthened layer; (2) Before or after fatigue,the numbers of dislocation are different in commercial purity titanium, but the samples strengthened by shot-peening or cold-rolling not only have twin shape and number change, but also have interactions between twin-grain boundary and twin-twin; (3) The strengthening effects of shot peening are more obvious than that of cold rolling is partly for the formation of quasi-twin paling in the surface.
Key words: titanium; twinning; fatigue; strengthening