D.Y.Li(Dept. of Mater. Sci & Eng.
,
The Pennsylvania State University
,
University Park
,
PA 16802
,
USA )B.Debray and J.A.Szpunar(Dept. of Metall. Eng.
,
McGill University
,
3450 Uuiversity Street
,
Molitreal
,
PQ
,
Canada H3A 2A7)
材料科学技术（英文）
The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. The stability and roughness of {111} and {100} solid/melt interfaces of fcc metals were investigated using a modified Temkin multi-layer model. It is demonstrated that {100}crystal/melt interface is more unstable and rougher than {111} interface. The effect of the stability of crystal/melt interface on the (100) texture formation in solidified fcc metals has been analysed and discussed.
关键词:
徐福松
,
耿浩然
,
王守仁
稀有金属材料与工程
采用机械合金化及退火工艺制备镧改性的TiAl3金属间化合物.通过X射线衍射、粒度分析、透射电镜、硬度、延伸率及断裂韧性研究镧对TiAl3显微组织以及室温力学性能的影响.结果表明:添加镧可使DO22型TiAl3的晶体结构向有序立方Ll2型转化,断裂韧性最大提高143.75%,可有效改善其室温脆性.镧的加入使TiAl3的硬度有所损失,试样的室温维氏硬度为3450-3500 MPa.
关键词:
镧
,
Ll2-TiAl3
,
机械合金化
,
断裂韧性
卢志明
,
陈冰冰
,
高增梁
材料工程
doi:10.3969/j.issn.1001-4381.2007.10.002
采用T形楔形张开加载(T-WOL)恒位移试样,进行16MnR钢在无水液氨环境的应力腐蚀实验.实验中采用了8只预裂纹试样,分别加载到不同应力强度因子K1值,放入盛有液氨的实验容器中.试样定期取出测量裂纹的长度,经总共3450h应力腐蚀实验,测得各试样的裂纹扩展速率在0.08×10-8～3.54×10-8 mm/s之间.结果表明:16MnR材料在无水液氨环境中裂纹基本没有扩展,其应力强度因子临界值KISCC大于90 MPa√m.同时分析了应力腐蚀开裂机理和影响其应力腐蚀行为的介质与材料因素.
关键词:
液氨
,
应力腐蚀
,
16MnR钢
,
临界应力强度因子
