摘要
The compressive yielding phenomenon of titanium alloys is not as focused and sufficiently ascertain as the tensile yielding phenomenon.In the present work,the peculiar compressive yielding behavior and the different dynamic responses of three different initial microstructures(singleβ,clavateβand lamellarβ)were investigated in an attractive metastableβtitanium alloy Ti-5553 using electron microscopes/crystallographic calculation/crystal plastic finite element simulation.Results reveal that the distinct compressive yielding behavior,steep peaks of sudden drop in the initial stage(very small true strain 0.03)of stress loading have appeared in the compression stress-strain curves except for the lamellarβinitial microstructure.Dislocation slip is the essential mechanism of the initial yielding behavior.Interlaced multiple-slip bands formed in the singleβinitial microstructure during the warm deformation process.A small quantity of single slip bands was observed in the deformed clavateβinitial microstructure.The abundant varied nano/ultrafineβsprecipitates were nucleated dynamically and dispersedly in all the three deformed initial microstructures.The multiple-slip bands formation and substantial nanoscaleβsresult in the highest peak of flow stress for singleβinitial microstructure.The compressive slip bands are formed early in the elastic–plastic deformation stage.As the increasing strain,the sample showed a significant compressive bulge,or eventually forming a strong adiabatic shear band or crack.These results are expected to provide a reference for the study of deformation behavior and mechanical properties of metastableβtitanium alloys.
The compressive yielding phenomenon of titanium alloys is not as focused and sufficiently ascertain as the tensile yielding phenomenon. In the present work, the peculiar compressive yielding behavior and the different dynamic responses of three different initial microstructures(single β, clavate βand lamellar β) were investigated in an attractive metastable β titanium alloy Ti-5553 using electron microscopes/crystallographic calculation/crystal plastic finite element simulation. Results reveal that the distinct compressive yielding behavior, steep peaks of sudden drop in the initial stage(very small true strain 0.03) of stress loading have appeared in the compression stress-strain curves except for the lamellar β initial microstructure. Dislocation slip is the essential mechanism of the initial yielding behavior.Interlaced multiple-slip bands formed in the single β initial microstructure during the warm deformation process. A small quantity of single slip bands was observed in the deformed clavate β initial microstructure. The abundant varied nano/ultrafine βsprecipitates were nucleated dynamically and dispersedly in all the three deformed initial microstructures. The multiple-slip bands formation and substantial nanoscale βsresult in the highest peak of flow stress for single β initial microstructure. The compressive slip bands are formed early in the elastic – plastic deformation stage. As the increasing strain, the sample showed a significant compressive bulge, or eventually forming a strong adiabatic shear band or crack.These results are expected to provide a reference for the study of deformation behavior and mechanical properties of metastable β titanium alloys.
基金
supported by National Natural Science Foundation of China(51801156)
Major State Research Development Program of China(2016YFB0701305)
Natural Science Basic Research Plan in Shaanxi Province of China(2018JQ5035)
the Fundamental Research Funds for the Central Universities(G2017KY0310).
作者简介
Corresponding author:Jiangkun Fan,State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an,710072,China.E-mail address:jkfan@nwpu.edu.cn
