Temperature dependence of pressure sensitive flow in bulk metallic glass composites  

作　　者：Priyanka Saini Yakai Zhao Biao Li Long Zhang U.Ramamurty R.L.Narayan 

机构地区：[1]Department of Materials Science and Engineering,Indian Institute of Technology,Delhi 110016,India [2]School of Mechanical and Aerospace Engineering,Nanyang Technological University,Singapore 639798,Republic of Singapore [3]Institute of Materials Research and Engineering,Agency for Science,Technology and Research,138634,Republic of Singapore [4]Shi-changxu Innovation Center for Advanced Materials,Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China

出　　处：《Journal of Materials Science & Technology》2024年第14期165-175,共11页材料科学技术（英文版）

基　　金：support provided by the Science and Engineering Research Board,Department of Science&Technology(No.SRG/2020/000095);the Prime Minister Fellowship(PMRF)(No.PMRF/2021/1401226);support of the National Natural Science Foundation of China(No.52171164);the National Key Laboratory of Science and Technology on Materials under Shock and Impact(No.WDZC2022–13);the Youth Innovation Promotion Association CAS(No.2021188).

摘　　要：The constraint factor,C,defined as hardness,H,to the yield strength,σ_(y),ratio,is an indirect measure of the pressure sensitivity in materials.Previous investigations determined that while C is less than 3 for crystalline materials,and remains invariant with change in temperature,it is greater than 3 for bulk metallic glasses(BMGs)and increases with increasing temperature,below their glass transition temper-ature,T_(g).In this study,the variations in C for two BMG composites(BMGCs),which have an amorphous matrix and in situ precipitated crystallineβ-Ti dendrites,which in one case transforms under stress toα”-Ti and deforms by slip in the other,as a function of temperature are examined and compared with that of a BMG.For this purpose,instrumented indentation tests,with a Berkovich tip,and uniaxial com-pression tests were performed to measure the H andσ_(y),respectively,on all alloys and their constituents at temperatures in the range of 0.48 T_(g) and 0.75 T_(g).σ_(y) and H of the BMGC with transforming dendrites(BMGC-T)increase and remain invariant with increasing temperature,respectively.Alternately,in BMG and the BMGC with non-transforming dendrites(BMGC–NT),the same properties decrease with increas-ing temperature.BMGC-T has the highest C of∼4.93 whereas that of BMGC–NT and BMG are∼3.72 and∼3.28,respectively,at 0.48 T_(g).With increasing temperature,C of the BMG and BMGC–NT increases with temperature,but that of the BMGC-T decreases.The values of C and their variations as a function of temperature were explained by studying the variation of pressure sensitivity of the amorphous phase and concluding that the plastic flow in BMGCs under constrained conditions,such as indentation,is con-trolled by the flow resistance of the amorphous matrix whereas that in uniaxial compression,which is only partially constrained,is controlled by plasticity in both the dendrites and matrix.

关 键 词：Bulk metallic glass composites HARDNESS Pressure sensitivity Martensitic transformation 

分 类 号：TG139.8[一般工业技术—材料科学与工程]