Finite element analysis of small-scale hot compression testing  

作　　者：Patryk Jedrasiak Hugh Shercliff 

机构地区：[1]Department of Engineering,University of Cambridge,Trumpington St,Cambridge,CB21PZ,UK

出　　处：《Journal of Materials Science & Technology》2021年第17期174-188,共15页材料科学技术（英文版）

基　　金：Light Form,a UK Engineering and Physical Sciences Research Council(EPSRC)programme grant(EP/R001715/1)。

摘　　要：This paper models hot compression testing using a dilatometer in loading mode.These small-scale tests provide a high throughput at low cost,but are susceptible to inhomogeneity due to friction and temperature gradients.A novel method is presented for correcting the true stress-strain constitutive response over the full range of temperatures,strain-rates and strain.The nominal response from the tests is used to predict the offset in the stress-strain curves due to inhomogeneity,and this stress offsetΔσis applied piecewise to the data,correcting the constitutive response in one iteration.A key new feature is the smoothing and fitting of the flow stress data as a function of temperature and strain-rate,at multiple discrete strains.The corrected model then provides quantitative prediction of the spatial and temporal variation in strain-rate and strain throughout the sample,needed to correlate the local deformation conditions with the microstructure and texture evolution.The study uses a detailed series of 144 hot compression tests of a Zr-Nb alloy.While this is an important wrought nuclear alloy in its own right,it also serves here as a test case for modelling the dilatometer for hot testing of high temperature alloys,particularly those with dualα-βphase microstructures(such as titanium alloys).

关 键 词：Finite element analysis Process modelling Hot compression testing UPSETTING Zr alloys Ti alloys 

分 类 号：TG115.5[金属学及工艺—物理冶金]