(1.清華大學(xué) 力學(xué)工程系，北京 100084；
2.清華大學(xué) 機(jī)械工程系，北京 100084)
摘 要: 對傳統(tǒng)的靜態(tài)剪切流變實(shí)驗(yàn)方法進(jìn)行了改進(jìn)，研究了不同初生α相形態(tài)半固態(tài)A356合金的流變規(guī)律。通過對實(shí)驗(yàn)結(jié)果進(jìn)行分析， 提出用6個特征參數(shù)描述半固態(tài)A356合金的靜態(tài)剪切流變特征：加載瞬時(shí)切變γ1，卸載瞬時(shí)恢復(fù)切變γ2，加載過程總切變γ3，卸載穩(wěn)定狀態(tài)下的切變γ4，加載時(shí)間t1及卸載穩(wěn)定時(shí)間t2。采用回歸分析得到流變參數(shù)與切變應(yīng)力、初生α相組織以及固相體積分?jǐn)?shù)之間的關(guān)系，為系統(tǒng)評定半固態(tài)A356合金的流變行為提供了實(shí)驗(yàn)依據(jù)。
關(guān)鍵字: A356合金；初生α相；流變行為；靜態(tài)剪切
A356 alloy with different morphology
of primary α phases
ZENG Da-ben2
（1.Engineering Mechanics Department, Tsinghua University,
Beijing 100084, China;
2.Mechanical Engineering Department, Tsinghua University，
Beijing 100084，China）
Abstract:Traditional static shear tests were revised so as to study the rheological behavior of semisolid A356 alloy with different microstructure morphology. Sixcharacteristic parameters，consisting of transient shear strain γ1 after loading，transient recovery shear strain γ2 after unloading，total shear strain γ3 during the period of loading，residual shear strain γ4 after unloading，time t1 of loading and time t2 between the initial unloading and the steady state after unloading，were put forward on the basis of analysis of different kinds of rheological curves. T he relations of characteristic parameters to shear stress， morphology of primary α phases， as well as solid fraction were obtained by regression analysis，so that the rheological behavior of semisolid A356 alloy can be evaluated systematically.
Key words: A356 alloy；primary α phase；rheological behavior；static shear
