液力挤压钨合金的微观破断特征及变形强化机制  

Microstructure fracture and deformation strengthening mechanism of hydraulic extrusion WHA

作　　者：王换玉[1] 才鸿年 

机构地区：[1]北京航空航天大学材料科学与工程学院 [2]兵总科技委,北京100081

出　　处：《材料科学与工艺》2007年第5期689-692,共4页Materials Science and Technology

基　　金：国防科工委基础科研计划资助项目(Z0900E006).

摘　　要：研究了93钨合金材料不同液力挤压的微观破断过程及变形强化机制.结果表明,裂纹的扩展首先萌生于合金中最薄弱的部位,即钨颗粒与钨颗粒的界面之间.随着挤压变形量的增大,裂纹的传播途径由粘结相向钨颗粒转移,所带来的最终效果是微观组织的"纤维化"和钨颗粒的穿晶解理比例越来越大,最终导致钨合金整体强度不断提高.同时在挤压过程中,合金组成相中的位错密度随变形量的增加而不断增大,钨颗粒与粘结相及钨颗粒之间的界面成为位错滑移的障碍,位错在滑移过程中遇到界面的障碍而不断地塞积,导致W-M界面结合强度及W-W界面结合强度增大,最终使得合金的变形抗力增大,合金的强度增大.The micro-fracture mechanism and strengthening mechanism of hydraulic extruding tungsten alloy were discussed. Results show that the crack spread firstly comes up in the meakest region between tungsten par- ticles. And its spread paths are changed from viscous phase to tungsten particles with increasing deformation lev- els, so the fibrous microstructure and more proportion of penetrating crystal fracture of tungsten particles are ob- tained,and the strength of tungsten alloy is improved. The dislocation between tungsten particles and viscous phases is constantly grown and accumulated during extrusion. The alloy＇ s deformation force is also largely multi- plied because of increasing dislocation density. Final effect is that the strength of tungsten alloy is increased.

关 键 词：液力挤压 钨合金 微观破断 变形 强化 

分 类 号：TG146.4[一般工业技术—材料科学与工程]