铝硅合金中针状铁相的断裂现象  

Fracture Phenomenon of Needle-like Iron Phase in Al Si Alloy

作　　者：印飞[1] 杨江波[1] 王亦新[1] 王国祥[1] 孙宝德[1] 

机构地区：[1]上海交通大学

出　　处：《特种铸造及有色合金》2001年第2期1-3,共3页Special Casting & Nonferrous Alloys

基　　金：国家重大基础研究规划项目 !(973专项G1 9990 6490 0 )

摘　　要：铝硅合金中的 β铁相由于会形成很长的针状组织 ,对合金的力学性能有害 ,在定向凝固试验中发现 ,在过渡区 ,针状铁相出现断裂现象。可以认为这种断裂现象与非平衡热处理中铁相的分裂变短 ,具有相同的机理。但由于在定向凝固条件下 ,针状铁相在一个更大的温度区间中保温和凝固 ,在一定条件下 ,针状铁相可以分解得更快更短。从局部看 ,铁相可分解为长宽比相近的粒状组织。这种粒状组织 ,与针状铁相相比 ,对合金性能的影响要小得多 。The formed long needle like β Fe phase in Al Si alloy is harmful to mechanical properties of the alloy. It was found during directional solidification that fracture phenomenon of needle like iron phase in transition zone occurs. It was considered the mechanism of the fracture phenomenon is the same as split off of iron phase in non equilibrium heat treatment. But in the given condition,the needle like iron phase is held and solidified in a wider range temperature interval during directional salidification so as to quickly split into short one. Iron phase has been split into granular structure with near length/width ratio in some local areas. This kind of granular structure is less harmful to the properties of the alloy than the needle like iron phase, and even can be functional to strengthen structure.

关 键 词：铝硅合金 针状铁相 溶断 断裂 

分 类 号：TG136.1[一般工业技术—材料科学与工程] [金属学及工艺—合金] TG146[金属学及工艺—金属学]