부산대학교 도서관

The microstructure, damprng behavior and mechanical properties of direciionally solidiiied MnCu-based alloys with different chemical compoiiioon gradients were studied via uimg dynamic thermomechanical analyzer, Opiical Microscope, X-Ray Diffractometer and Scanning Electron Microscope. The results show that duiing direciional solidieicaeion,the dendiite spaing gradually decreaseslthe degree of component segregaiion increases,and the phase consiituent becomes a ingle parent phase with the addieion of alloying llemente. The compoeieion supercooing caused by entropy increase makes the dendiites prone to fracture. The addiiion of nickll and iron Increases the internal fiiciion value of the low-temperature twin, after adding Zn,the Internal fiiciion value of the MnCuNiFeZn alloy at 673 K iises to 0. 023. With the increase of mixed entropy,the teniile strength and elongaiion of the three alloys increase lineaely,and the llope of the stable holing seciion of the alloy strain hardening rate is poeieively comlated with the entropy of mixing. [ABSTRACT FROM AUTHOR]