The Experimental Investigation Of Liquidus Projection And The 85 At.%Al Isothermal Section At 450? Of The Al-Cu-Mn-Zn Quaternary System

The present work is experimental studying the liquidus projection in Al-rich part for Al-Mn-Zn ternary system,and the 85 at.%A1 isothermal section at 450 ? and liquidus projection for the Al-Cu-Mn-Zn quaternary system.Firstly,the phase diagram of Al-Cu-Mn-Zn was calculated basing on TCAL2-A1 alloy thermodynamic database by Thermo-Cal software,and then the composition of appropriate alloys were selected basing on the calculated phase diagram.Secondly,the as-cast and equilibrium alloys were examined by optical microscope(OM),X-ray diffraction analysis(XRD),electron scanning microscopy with band spectroscopy(SEM-EDS),and differential thermal analyzer(DSC)et al.By comprehensive analysis the experimental data and related literatures,we got the information of the liquidus projection at Al-rich part of Al-Mn-Zn ternary system,and the 85 at.%A1 isothermal section at 450 ? and liquidus projection of Al-Cu-Mn-Zn quaternary system were determind.According our present experimental results,a ternary compound?2(Al11Mn3Zn2)is detected in the liquid-rich surface of the Al-Mn-Zn ternary system,and three zero-variable balances are preliminarily estimated,L+Al8Mns ??2+Al4Mn,L+Al4Mn ? ?2+Al6Mn(640?),L+Al6Mn?(Al)+?2(57?);The 85 at.%Al isothermal section at 450?for Al-Cu-Mn-Zn quaternary system contains two binary compounds Al2Cu and Al6Mn,and one ternary compound ?1(Al28Cu4Mn7);The isothermal section has two two-phase regions and two three-phase regions and no four-phase region is found in this syetem.The information of primary phase,liquids temperature and phase transfermation are summary and present also.