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摘要
Taking Ta-W alloy system as an example, the concentration formulae of alloy genes of DO3-type alloys in BCC structures were derived on the basis of the theory of alloy genes and the number of coordination atoms. The concentrations of alloy genes of DO3-TaW3 and DO3-Ta3W ordered alloys were calculated as functions of composition xW and ordering degree (s). When s=smax, the concentrations of alloy genes of stoichiometric DO3-TaW3 compound are equal to those of alloys, that is, x (8) (Ta) 0.25(at), x (4) (W) 0.5(at), x (8) (W) 0.25(at). The concentrations of alloy genes of stoichiometric DO3-Ta3W compound are also equal to those of alloys, that is, x (0) (Ta) 0.25(at), x (4) (Ta) 0.5(at), x (0) (W) 0.5(at). As ordering degree decreases, alloy genes of DO3-TaW3 and DO3-Ta3W ordered alloys will split. And the degree of splitting of alloy genes increases with the ordering degree decreasing. The atomic states and properties of DO3-TaW3 and DO3-Ta3W ordered alloys were calculated as a function of composition xW. The reason was pointed out that preparation of DO3-TaW3 and DO3-Ta3W intermetallic compounds is difficult due to small differences in their cohesive energies. It will provide theoretical guidance for the scientific designation to new candidate for ultrahigh- temperature materials in areo-engine applications.
- 出版日期2018-7
- 单位中南大学
