(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽(yáng) 471023；
2. 有色金屬共性技術(shù)河南省協(xié)同創(chuàng)新中心，洛陽(yáng) 471023)
摘 要: 研究擠壓溫度對(duì)鑄態(tài)Mg-2.0Zn-0.5Zr-3.0Gd生物鎂合金組織、力學(xué)性能及耐腐蝕性能的影響。結(jié)果表明：擠壓溫度在330~350 ℃時(shí)，動(dòng)態(tài)再結(jié)晶的體積分?jǐn)?shù)隨擠壓溫度的升高而增加；在350~370 ℃時(shí)，動(dòng)態(tài)再結(jié)晶的體積分?jǐn)?shù)隨溫度的升高而降低。擠壓態(tài)合金的析出相主要由納米級(jí)的棒狀(Mg, Zn)3Gd相和新析出的顆粒狀Mg2Zn11相組成。合金的力學(xué)性能與動(dòng)態(tài)再結(jié)晶晶粒的體積分?jǐn)?shù)成正比關(guān)系。擠壓溫度為350 ℃時(shí)，合金的抗拉強(qiáng)度、屈服強(qiáng)度及伸長(zhǎng)率分別為(247±3) MPa、(214±3) MPa和(26.7±1.1)%。隨著擠壓溫度的升高，合金的腐蝕速率先減小后增大，擠壓溫度為350 ℃時(shí)，合金的靜態(tài)腐蝕速率及析氫腐蝕速率分別為0.614 mm/a和0.598 mm/a。
關(guān)鍵字: 鎂合金；微觀組織；生物腐蝕性能；力學(xué)性能
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of Nonferrous Metals, Luoyang 471023, China）
Abstract:Effects of the extrusion temperature on the microstructure, mechanical properties and corrosion resistance of as-cast Mg-2.0Zn-0.5Zr-3.0Gd biomedical magnesium alloy were investigated. The experimental results show that the volume fraction of dynamic recrystallized (DRXed) microstructure increases with increasing the extrusion temperature from 330 ℃ to 350 ℃, but decreases as the temperature increased further to 370 ℃. The precipitated phases of extruded alloys are composed of nanoscale rod-like (Mg, Zn)3Gd and granular Mg2Zn11 phase. The Mg2Zn11 precipitated phase is a new precipitated phase in the extrusion process. The mechanical properties of extruded alloys are proportional to the volume area fraction of the DRXed grains. When the extrusion temperature is 350 ℃, the ultimate tensile strength, yield strength and ultimate tensile strength of extruded alloys are (248±3) MPa, (228±3) MPa and (29.4±0.9) %, respectively. The corrosion rates of the extruded alloys decrease initially and then increase with increasing the extrusion temperature from 330 ℃ to 370 ℃. The corrosion rates of the alloy were determined to be 0.614 mm/a and 598 mm/a, respectively, in mass loss and hydrogen evolution methods when the extrusion temperature is 350 ℃.
Key words: magnesium alloy; microstructure; biocorrosion property; mechanical property
