Enhanced strength and ductility in a powder metallurgy Ti material by the oxygen scavenger of CaB_(6)  

作　　者：Yu Pan Jinshan Zhang Jianzhuo Sun Yanjun Liu Ce Zhang Rui Li Fan Kuang Xinxin Wu Xin Lu 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,Institute of Engineering Technology,National Engineering Research Center for Advanced Rolling Technology,University of Science and Technology Beijing,Beijing 100083,China [2]School of Materials Science and Engineering,Nanjing Institute of Technology,Nanjing 211167,China

出　　处：《Journal of Materials Science & Technology》2023年第6期132-142,共11页材料科学技术（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.51874037 and 51922004);the Beijing Natural Science Foundation(No.2212035);the National Postdoctoral Program for Innovative Talents(No.BX20220034);the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-19005C1Z and 00007718);the State Key Lab of Advanced Metals and Materials,University of Science and Technology Beijing(Nos.2021Z-03 and 2022Z-14).

摘　　要：The challenge of producing a high-ductility titanium(Ti)material using inexpensive high-oxygen hydride-dehydride(HDH)Ti powder is hereby addressed by the incorporation of CaB_(6)oxygen-scavenger.The oxygen-scavenging behavior,microstructure evolution,mechanical behavior and improvement mechanism were systematically investigated.A continuous TiO_(2)oxide layer with a thickness of approximately 9.3 nm is presented on the HDH Ti powder surface.The oxide layer will dissolve into Ti matrix during sintering,making the increase of c/a value and leading to the Ti-Ti bonds developing from plastic metal bonds to-ward brittle covalent bonds.The CaB_(6)addition can scavenge O impurity and make a significant increase in tensile ductility forα-Ti matrix.A small addition of 0.2 wt.%CaB_(6)provides a superior tensile elongation of 22.2%for Ti material,almost three times as high as that of pure Ti(7.5%).The increase of defor-mation twining activity and grain refinement are responsible for the improved ductility.Furthermore,the CaB_(6)oxygen-scavenger can react with the surface oxide layer to in-situ form rod-like TiB and granular CaTiO_(3)reinforcements,refining the coarse near equiaxed grain ofα-Ti matrix into fine equiaxed crys-tals.The multiple mechanisms of grain-boundary strengthening,load-bearing strengthening of TiB and Orowan strengthening of CaTiO_(3)nanoparticles work together to increase the tensile strength of Ti/CaB_(6)composites.This work offers an effective method to fabricate high-performance Ti material using inex-pensive high-oxygen HDH Ti powder.

关 键 词：TITANIUM Powder metallurgy SINTERING OXYGEN Mechanical properties 

分 类 号：TG146.23[一般工业技术—材料科学与工程]