中文摘要：

采用ProCAST软件系统研究了LMCCLiquidMetalCooling)以及HRSCHighRateSolidification)工艺下，不同工艺参数对单晶铸件凝固过程中纵向温度梯度、温度梯度角、凝固界面位置的影响。结果表明：HRS工艺受型壳厚度影响很小，型壳表面的辐射散热是HRS工艺的主要影响因素，型壳的导热或者型壳和合金之间的换热是LMC工艺的主要影响因素；提高保温炉温度有利于提高纵向温度梯度;拉速是影响定向凝固最重要的参数，随拉速的增加，单晶铸件的纵向温度梯度先增大后减小，因此，制备不同合金铸件时应当采用不同的拉速；不同浇注温度时，经过l〇min的静置时间后，单晶铸件的初始温度分布趋于一致，对后续凝固过程影响很小。提出了以纵向温度梯度G//、温度梯度角6以及凝固界面位置氏考察定向凝固工艺参数优劣的标准，纵向温度梯度、温度梯度角、凝固界面位置是评价定向凝固参数优劣的有效手段。

英文摘要：

A new m e th o d is proposed to evaluate th e process param eters b y th e s o lid-liq u id in te rfa cep o s itio n,th e rm a l g ra d ie n t angle and the a x ia l th e rm a l g ra d ie n t.T h e effects o f th e process param eterson th e s o lid-liq u id in te rfa c e p o s itio n,th e rm a l g ra d ie n t angle and th e a xia l th e rm a l g ra d ie n t w ere s im u latedb y P ro C A S T u sing L M C(L iq u id M e ta l C o o lin g)and H R S(H ig h R ate S o lid ific a tio n)processes.T h e re s u lts show th a t H R S process is lit tle a ffected b y th e m o ld th ic k n e s s,the d o m in a n t heat tra n s fe rfa c to r in H R S is ra d ia tio n fro m th e m o ld su rfa ce,and th e d o m in a n t heat tra n s fe r fa c to r in L M C e ith e rm o ld th e rm a l c o n d u c tiv ity o r m o ld-m e ta l in te rfa c e heat tra n s fe r;in creasing fu rn a ce te m p e ra tu re isb e n e ficia l to increase th e a x ia l th e rm a l g ra d ie n t;th e w ith d ra w a l ra te is th e m o st im p o rta n t process param e te r w h ic h s ig n ific a n tly a ffe cts th e th e rm a l fie ld d u rin g s o lid ific a tio n,as th e w ith d ra w a l ra te in creases,th e a xia l th e rm a l g ra d ie n t fir s t increases and th e n decreases,th e re fo re,it is necessary to apply d iffe re n t w ith d ra w a l rates fo r d iffe re n t a llo ys.A fte r h o ld in g lO m in at d iffe re n t p o u rin g te m p e ra ture s,a u n ifo rm te m p e ra tu re is achieved,and it has s lig h t in flu e n c e on th e subsequent s o lid ific a tio n.I t has been p u t fo rw a rd th a t th e s o lid-liq u id in te rfa c e p o s itio n,th e rm a l g ra d ie n t angle and th e a xialth e rm a l g ra d ie n t can be u tiliz e d as a se ria l o f e ffic ie n t analysis standards fo r o p tim iz a tio n o f processc o n d itio n s ind e pe n d e n t o f casting geo m e try.