摘要
对喷射沉积Al- 30 %Si合金组织及其在半固态保温过程中的转变进行了试验研究 .喷射沉积Al-30 %Si合金沉积态组织是由细小的Si相与α基体组成 ,提出这种组织是由于离异共晶引起的 ,并运用该机制对组织中Si相的集聚进行了解释 ,认为其形成机制为 :其一 ,在沉积阶段凝固过程中大量细小的Si发生了粗化和团聚 ;其二 ,大量的Si在沉积时会发生碰撞而靠在一起 ,在随后的离异共晶凝固过程中 ,共晶硅附着在初生硅上从而将原来相互独立的Si联结在一起 .在半固态保温过程中 ,基体发生熔化而出现球形α ,而Si相则发生粗化 。
The microstructure of spray deposited Al-30Si alloy and its evolution in the semi solid state holding process has been studied. A divorce eutectic mechanism is presented on basis of believing that the final microstructure of spray deposited hypereutectic alloy is the result of the development of a divorce eutectic which appears in the depositing solidification process. The aggregation of Si phase in the matrix is well explained by this mechanism. Further, the microstructure transformation during the semi solid state holding happens when the globular shape α-phase appears in the melting of the matrix and the Si coarsening takes place as well. The Si coarsening speed depends on both holding temperature and holding time.
出处
《材料科学与工艺》
EI
CAS
CSCD
2001年第2期162-165,共4页
Materials Science and Technology
