利用原位观察的方法研究了全片层(Fully Lamellar,FL)组织与双态(Duplex,DP)组织高铌TiAl合金在750℃下的拉伸力学行为.结果表明:DP组织具有较好的抗拉强度和塑性,其抗拉强度为958MPa,断面收缩率为45.1%,FL组织抗拉强度较低且几乎没有塑性;随着拉伸应力的增加,DP组织合金试样表面存在一个大量裂纹萌生和扩展的过程,这些裂纹均匀分布在试样表面,主要以萌生为主,几乎难以扩展,而在FL组织中只能观察到少量的裂纹萌生现象;拉伸断裂后的DP组织合金的裂纹是由多个孔洞合并而成,呈蠕虫状且尺寸很小,FL组织中与拉伸方向垂直或呈一较大夹角的片层团界及片层界较易萌生裂纹,在临近断口区域,裂纹主要以穿层扩展为主.
参考文献
[1] | 陈国良;林均品.有序金属间化合物结构材料物理金属学基础[M].北京:冶金工业出版社,1999:285-341. |
[2] | 张永刚;韩雅芳;陈国良.金属间化合物结构材料[M].北京:国防工业出版社,2000:762-779. |
[3] | KIM Y W .Intermetallic alloys based on gamma titanium aluminide[J].JOM,1989,41(07):24-30. |
[4] | KIM Y W .Ordered intermetallic alloys,partⅢ:gamma titanium aluminides[J].JOM,1994,46(07):30-39. |
[5] | 邓忠勇,黄伯云,贺跃辉,刘咏.显微组织对TiAl基合金超塑性的影响[J].材料工程,1999(12):26-27. |
[6] | CHAN K S;ONSTOTT J;KUMAR K S .The fracture resist ance of a binary TiAL alloy[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,2000,31(01):71-80. |
[7] | CHAN K S;KIM Y W .Relationships of slip morphology,microcracking,and fracture resistance in a lamellar TiAL alloys[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1994,25(06):1217-1228. |
[8] | HUANG S C;HALL E L .Plastic deformation and fracture of binaryTiAlbasealloy[J].METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE,1991,22(02):427-439. |
[9] | CHAN K S;KIM Y W .Influence of microstructure on crack-tip micromechanics and fracture behaviors of a two phase TiAl alloy[J].MetailTransA,1992,23(06):1663-1677. |
[10] | Kim YW. .EFFECTS OF MICROSTRUCTURE ON THE DEFORMATION AND FRACTURE OF GAMMA-TIAL ALLOYS[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1995(0):519-533. |
[11] | C. Mercer;W. O. Soboyejo .Hall-petch relationships in gamma titanium aluminides[J].Scripta materialia,1996(1):17-22. |
[12] | CHU W Y;THORNPSON A W .Effects of grain size on yield strength inTiAL[J].ScriptaMetall,1991,25(03):641-644. |
[13] | SOBOYEJO W O;SCHWARTZ D S;SASTRY S M L .An in vestigation of the fracture behavior of gamma based titanium aluminides:effects of annealing in the α+γ and α2 +γ phase fields[J].MetallTrans A,1992,23(07):2039-2059. |
[14] | 孔凡涛,陈子勇,田竞,陈玉勇.提高TiAl基合金室温塑性的方法[J].稀有金属材料与工程,2003(02):81-86. |
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