Centimeter-scale-diameter Co-based bulk metallic glasses with fracture strength exceeding 5000 MPa  

作　　者：ZHANG Tao YANG Qin JI YunFei LI Ran PANG ShuJie WANG JianFeng XU Tao 

机构地区：[1]Key Laboratory of Aerospace Materials and Performance of Ministry of Education, School of Materials Science and Engineering, BeihangUniversity, Beijing 100191, China

出　　处：《Chinese Science Bulletin》2011年第36期3972-3977,共6页

基　　金：supported by the National Basic Research Program of China (2007CB613900);the National Natural Science Foundation of China (51071008)

摘　　要：Co48-xFexCr15Mo14C15B6Er2 (x = 2.5 and 5) bulk metallic glasses (BMGs) with critical size (dc) up to 15 mm in diameter were synthesized by copper mold casting. Co43Fe5Cr15Mo14C15B6Er2 BMG has a wide supercooled liquid region (84 K) and ultrahigh fracture strength exceeding 5000 MPa,which is the highest value for reported metallic glasses with dc exceeding 1 cm. Furthermore,the Poisson ratio,Young modulus,shear modulus and bulk modulus of this alloy were evaluated to be 0.31,217 GPa,82 GPa and 214 GPa,respectively. The ideal configurational entropy of Co48-xFexCr15Mo14C15B6Er2 (x = 0 and 5) has been calculated. The introduction of the similar element Fe in the Fe-free Co-Cr-Mo-C-B-Er alloy will be beneficial to increasing the ideal config-urational entropy and depressing the critical cooling rate to achieve greater glass-forming ability. The combination of superior glass-forming ability and ultrahigh fracture strength makes the present Co48-xFexCr15Mo14C15B6Er2 (x = 2.5 and 5) BMGs promising candidates as advanced structural materials.Co48-xFexCr15Mo14C15B6Er2 （x = 2.5 and 5） bulk metallic glasses （BMGs） with critical size （dc） up to 15 mm in diameter were synthesized by copper mold casting. Co43Fe5Cr15Mo14C15B6Er2 BMG has a wide supercooled liquid region （84 K） and ultrahigh fracture strength exceeding 5000 MPa,which is the highest value for reported metallic glasses with dc exceeding 1 cm. Furthermore,the Poisson ratio,Young modulus,shear modulus and bulk modulus of this alloy were evaluated to be 0.31,217 GPa,82 GPa and 214 GPa,respectively. The ideal configurational entropy of Co48-xFexCr15Mo14C15B6Er2 （x = 0 and 5） has been calculated. The introduction of the similar element Fe in the Fe-free Co-Cr-Mo-C-B-Er alloy will be beneficial to increasing the ideal config-urational entropy and depressing the critical cooling rate to achieve greater glass-forming ability. The combination of superior glass-forming ability and ultrahigh fracture strength makes the present Co48-xFexCr15Mo14C15B6Er2 （x = 2.5 and 5） BMGs promising candidates as advanced structural materials.

关 键 词：大块金属玻璃 断裂强度 钴基 直径 厘米级 玻璃形成能力 非晶合金 体积弹性模量 

分 类 号：TG139.8[一般工业技术—材料科学与工程] TB33[金属学及工艺—合金]