Effect of alloying elements (Ni, Co, Cr, and Sn) on the mechanical properties of W–Cu alloy system predicted from first principles

• Published in: Journal of materials science 2024-10, Vol.59 (39), p.18776-18793
• Main Authors: Ning, Zengye, Li, Xiuqing, Wei, Shizhong, Liang, Jingkun, Wu, Jie, Zhang, Xinyu, Pei, Haiyang, Xu, Liujie, Zhou, Yucheng
• Format: Article
• Language: English
• Subjects: Alloy systems; Alloying effects; Alloying elements; Bonded joints; Bonding strength; Characterization and Evaluation of Materials; Charge density; Charge materials; Chemical bonds; Chemistry and Materials Science; Chromium; Classical Mechanics; Copper; Covalent bonds; Crystallography and Scattering Methods; Doping; Elastic properties; Electron distribution; Electronic structure; First principles; Hardness; Materials Science; Mechanical properties; Metals & Corrosion; Nickel base alloys; Orbitals; Polymer Sciences; Solid Mechanics; Structural analysis; Tin; Toughness; Tungsten base alloys
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-024-10300-8

In order to explore the reasons for the influence of alloying element X (X = Ni, Co, Cr, and Sn) on the strength, hardness and toughness of W–Cu alloy, this paper calculated the elastic constants and electronic structures of W–Cu alloy and W–X–Cu alloy based on first principles, and quantitatively evaluated the influence of alloying element X on the strength, hardness and toughness of W–Cu alloy from the atomic level. The results show that the W–Ni–Cu alloy system has the best strength and hardness when the doped content of Ni is 3.125%, and the alloy system has the best stiffness when the doped content of Cr is 12.5%. The electronic structure analysis shows that the charge density of Ni-3 d , Co-3 d , Cr-3 d and Sn-5p orbitals increases with the increase of alloyed element doping ratio. Alloyed atom doping generates new chemical bonds in the system, and weakens the hybridization between Cu 3 d and W 5 d orbitals, thus affecting the bonding strength of W–Cu bonds. W–X bond is always a strong covalent bond, which can make up for the weakening of W–Cu bond to a certain extent. W–Cu bond and W–X bond jointly determine the strength and hardness of the system. Alloying atom X also changes the electron distribution on the 3 d and 4 s orbitals of Cu atom, resulting in changes in the charge density between neighboring Cu atoms, which affects the toughness of the material system.