冷轧Al_(0.3)CoCrFeNi高熵合金退火再结晶组织和织构的演变

利用维氏硬度计(HV)、X射线衍射仪(XRD)、电子背散射衍射(EBSD)和透射电镜(TEM),研究了90%冷轧Al0.3CoCrFeNi高熵合金在900℃退火过程中的微观组织和织构演变规律。结果表明:退火0.5h合金发生完全再结晶,退火孪晶形成于再结晶面心立方(FCC)晶粒内;经退火1h后,富集Al-Ni原子的有序体心立方(BCC)相优先于FCC相的晶界处形核,且FCC相和BCC相均随着退火时间(1h~10h)的延长而发生晶粒长大。再结晶FCC相的织构组分主要为强{123},〈634〉S织构和强α-{110}纤维织构,{001}〈100〉立方织构随着退火时间的延长也逐渐转化为强织构;再结晶过程的进行使无择优取向的初始BCC晶核选择性长大,{111}〈112〉织构从而演变为强BCC相织构。     

In Situ Monitoring of Thermally Cycled Metal Matrix Composites by Neutron Diffraction and Laser Extensometry

A novel stroboscopic neutron diffraction data collection system has beendeveloped. In combination with scanning laser extensometry this has beenused to investigate the thermal cycling behaviour of SiC short fibrereinforced Al matrix composites. Three-dimensional unit cell finite elementmodels have been produced, incorporating matrix deformation both by creepand plasticity. Comparison of the experimental results with modelpredictions has allowed conclusions to be drawn about the deformationprocesses which dominate at different parts of the thermal cycle.