(中南大學(xué) 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 以高能球磨粉末為原料，研究元素鈷對固溶淬火態(tài)93W-Ni-Fe合金微觀結(jié)構(gòu)和性能的影響。對經(jīng)1 490 ℃燒結(jié)并保溫90 min的試樣在1 280 ℃固溶2 h，隨后在水中淬火，采用光學(xué)金相(OM)、掃描電鏡(SEM)及EDAX能譜等對樣品的組織形貌進行表征，采用準靜態(tài)拉伸實驗對合金的拉伸強度及伸長率進行測試，采用排水法對合金的相對密度進行測量。結(jié)果表明：當Co含量為0~0.9%(質(zhì)量分數(shù))時，隨著Co含量的增加，固溶淬火態(tài)93W-Ni-Fe合金的拉伸強度、伸長率和相對密度由不添加Co時的1 039 MPa、18.3%和99.3%分別提高到0.9%Co時的1 085.5 MPa、26.5%和99.4%；元素Co的適量加入能增加固溶淬火態(tài)合金中鎢晶粒的穿晶解理斷裂和粘結(jié)相的延性撕裂，改善合金組織，提高合金的性能；當元素Co含量超過0.9%時，隨著Co含量的增加，固溶淬火態(tài)93W-Ni-Fe合金的性能降低；當Co含量為1.5%時，合金的拉伸強度降至1 039.5 MPa，伸長率降至24.6%。
關(guān)鍵字: 93W-Ni-Fe合金；Co；固溶淬火； 微觀組織；力學(xué)性能
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The effects of Co addition on microstructure and mechanical properties of 93W-Ni-Fe alloy treated by solid-solution and water-quenching were investigated. The procedure, which was 2 h solid-solution at 1 280 ℃ and quickly quenching in water for samples sintered at 1 490 ℃ for 90 min, was performed. Optical microscope(OM), scanning electricity microscope (SEM) and EDAX energy spectrum were used to characterize the microstructure and compositions of the alloys, respectively. The strength and elongation of alloys were tested with quasi-static tensile testing machine, and the relative densities of the alloys were evaluated by using the Archimedes water immersion method. The results indicate that, when Co addition is in the range of 0−0.9%(mass fraction), with the increase of Co content, the tensile strength, elongation and relative density of 93W-Ni-Fe alloys treated by solid-solution and water-quenching increase from 1 039 MPa, 18.3% and 99.3% without Co addition to 1 085.5 MPa, 26.5% and 99.4% with 0.9%Co addition, respectively. Meanwhile, the mechanical properties are enhanced with some Co additions because of increasing the transcrystalline fracture and ductile tearing of the matrix in the solid-solution and water-quenching alloy. When the Co content exceeds 0.9%, the mechanical properties of 93W-Ni-Fe alloy treated by solid-solution and quenching are reduced, so the tensile strength and elongation of alloys reduce to 1 039.5 MPa and 24.6%, respectively with 1.5%Co addition.
Key words: 93W-Ni-Fe alloy; Co; solid-solution water-quenching; microstructure; mechanical properties
