(中南大學(xué) 粉末冶金國家重點實驗室, 長沙 410083)
摘 要: 采用球磨制備Mo-0.1Zr粉末，經(jīng)壓制成型、預(yù)燒、高溫?zé)Y(jié)和真空熱處理后，制備抗拉強度超過650 MPa、伸長率大于30%的高強韌Mo-0.1Zr合金，研究真空熱處理對合金性能與顯微組織的影響。結(jié)果表明：經(jīng)高溫?zé)Y(jié)后，Mo-0.1Zr合金與純Mo相比性能提高不明顯，斷口形貌呈明顯的沿晶脆性斷裂特征；但經(jīng)真空熱處理后，Mo-0.1Zr合金的性能顯著提高，抗拉強度提高了40%、伸長率從7.3%提高到31.2%，合金斷口也由沿晶脆性斷裂轉(zhuǎn)變?yōu)榇┚ыg性斷裂，且部分晶粒呈韌性撕裂特征。真空熱處理溫度對合金性能的影響很大，真空熱處理溫度過高容易使晶粒長大，導(dǎo)致性能提高程度下降；而真空熱處理溫度過低難以起到消除晶體缺陷的作用，對合金性能提高有限。
關(guān)鍵字: Mo-0.1Zr合金；抗拉強度；伸長率；沿晶斷裂；穿晶斷裂；韌性撕裂
high tenacious Mo-0.1Zr alloy
（State Key Laboratory of Powder Metallurgy, Central South University,
Changsha 410083, China）
Abstract:Mo-0.1Zr powder was prepared by ball-milling, then this powder was made into high tenacious alloy with tensile strength above 650 MPa and elongation above 30% after a series of processes including press forming, pre-sintering, high-temperature sintering, and vacuum heat treating. The effects of vacuum heat treatment on properties and microscopic structure of the alloy were investigated. The results show that, after sintering at high temperature, the properties of Mo-0.1Zr alloy have no obvious improvement compared with pure Mo, and its fracture exhibits an obvious characteristic of intergranular brittle rupture. However, after vacuum heat treatment, the performance of Mo-0.1Zr alloy rises obviously, tensile strength increases by 40%, elongation percentage increases from 7.3% to 31.2%, and alloy fracture translates from intergranular brittle rupture to transcytalline ductile rupture. At the same time, parts of the grains exhibit a characteristic of ductile tearing. The significant increase in performance of Mo-0.1Zr alloy after vacuum heat treatment is closely related to the elimination of vacancies and dislocations. However, an excessively high temperature will cause the grain growth, resulting in the decrease of increasing extent of alloy performance; an excessively low vacuum heat treatment temperature has little effect on increasing the alloy performance because it can hardly play a role in eliminating crystal defects.
Key words: Mo-0.1Zr alloy; tensile strength; elongation; intergranular rupture; transcytalline rupture; ductile tearing
