超高强块体非晶合金的研究进展

研制具有极限力学性能的金属材料一直是材料研究人员的梦想.超高强块体非晶合金是一类具有极高断裂强度(4 GPa)、高热稳定性(玻璃化转变温度通常高于800 K)和高硬度(通常高于12 GPa)的新型先进金属材料,其代表合金材料Co-Ta-B的断裂强度可达6 GPa,为目前公开报道的块体金属材料的强度记录值.本文系统地综述了该类超高强度块体非晶合金的组分、热学性能、弹性模量及力学性能,阐述了该类材料的研发历程;以弹性模量为联系桥梁,阐明了该类超高强块体非晶合金材料各物理性能的关联性,并揭示了其高强度、高硬度的价键本质.相关内容对于材料工作者了解该类超高强度金属材料的性能和特点,并推进该类材料在航空航天先进制造、超持久部件、机械加工等领域的实际应用有着重要意义.

Development of ultrahigh strength bulk metallic glasses

It is always desirable to develop bulk metal materials with extremely mechanical properties. Ultrahigh strength bulk metallic glass (BMG) is a kind of advanced metallic material with extremely high strength (above 4 GPa), high thermal stability (the glass transition temperature: normally above 800 K), and high hardness (normally above 12 GPa). A typical system of the ultrahigh strength BMG is Co-Ta-B alloy with a fracture strength of above 6 GPa, which is the highest value in the fracture strengths for all kinds of bulk metallic materials (including crystalline and amorphous ones) that we have known so far. In this paper, the compositions, thermal properties, elastic constants, and mechanical properties for all of the reported ultrahigh strength BMGs are summarized. The research progress of these BMGs is also introduced. The correlations among the characteristic temperature, elastic constants, hardness and mechanical properties are built, and the natures of chemical bonding for the ultrahigh strength and high hardness of these BMGs are revealed. The results relating to the structure and physical properties of this kind of ultrahigh strength BMG are significant for potential applications in advanced manufacture, super-durable components and machining.