CAJ | 학술논문

采用直流电沉积方法制备晶粒尺寸为15 nm的Ni-49.2%Co(质量分数)和16 nm的Ni-66.7%Co(质量分数)合金。采用XRD、TEM和MTS?810万能材料试验机对其微观结构和力学性能进行分析。结果表明：两种合金分别是单相FCC结构和FCC与HCP共存的双相结构。固溶强化和晶粒细化的作用使两种Ni-Co合金都具有很高的抗拉强度；且Co元素的引入降低材料的层错能，提高其应变硬化能力，使Ni-Co合金的塑性也明显提高；Ni-49.2%Co合金的抗拉强度(σb )和断裂伸长率(δ)分别为1650 MPa和9%，Ni-66.7%Co合金的σb和δ分别为2200 MPa和12%。Ni-66.7%Co合金中FCC和HCP结构相互协调，在变形过程中释放内应力，使材料应变硬化能力得以保持，所以获得更高的强度和塑性。
채용직류전침적방법제비정립척촌위15 nm적Ni-49.2%Co(질량분수)화16 nm적Ni-66.7%Co(질량분수)합금。채용XRD、TEM화MTS?810만능재료시험궤대기미관결구화역학성능진행분석。결과표명：량충합금분별시단상FCC결구화FCC여HCP공존적쌍상결구。고용강화화정립세화적작용사량충Ni-Co합금도구유흔고적항랍강도；차Co원소적인입강저재료적층착능，제고기응변경화능력，사Ni-Co합금적소성야명현제고；Ni-49.2%Co합금적항랍강도(σb )화단렬신장솔(δ)분별위1650 MPa화9%，Ni-66.7%Co합금적σb화δ분별위2200 MPa화12%。Ni-66.7%Co합금중FCC화HCP결구상호협조，재변형과정중석방내응력，사재료응변경화능력득이보지，소이획득경고적강도화소성。
Nanocrystalline Ni-49.2%Co (mass fraction) and Ni-66.7%Co (mass fraction) alloys were synthesized by direct current electrodeposition with grain sizes of 15 and 16 nm, respectively. The Ni-49.2%Co alloy shows single FCC phase, and Ni-66.7%Co alloy possesses a mixture structure of FCC and HCP phase. The microstructure and mechanical properties of were studied by XRD, TEM and tensile tests carried out on MTS?810 tester. The high strength of Ni-Co alloys is attributed to the grain refinement and solid-solution hardening effects. The addition of Co element decreases the stacking fault energy of nanocrystalline Ni alloy, which improves the strain hardening ability and thus enhances the ductility. The ultimate tensile strength (σb ) and elongation to failure (δ) of Ni-49.2%Co alloy are 1 650 MPa and 9%, respectively. Correspondingly, the σb and δ of Ni-66.7%Co alloy are 2 200 MPa and 12%, respectively. Cooperative deformation of the two phases releases the stress during deformation effectively, which contributes to the sustained high strain hardening and ductility of the Ni-66.7%Co alloy.