(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽 471023； 2. 有色金屬共性技術(shù)河南省協(xié)同創(chuàng)新中心，洛陽 471023)
摘 要: 利用光學(xué)顯微鏡、掃描電子顯微鏡、透射電子顯微鏡、失重測試、電化學(xué)測試與拉伸試驗研究熱擠壓與退火溫度對Mg-Zn-Zr-Ce生物鎂合金組織與性能的影響。結(jié)果表明：熱塑性變形后合金發(fā)生動態(tài)再結(jié)晶，合金的組織由細(xì)小的再結(jié)晶晶粒與未再結(jié)晶的晶粒組成；退火后變形晶粒發(fā)生再結(jié)晶，隨著退火溫度的升高，晶粒逐漸長大。當(dāng)退火溫度高于200 ℃時，合金的腐蝕電流密度(Jcorr)與平均晶粒尺寸(d)滿足Jcorr=a+bd-1/2方程。由該方程可推測出經(jīng)200 ℃退火3 h后，合金的腐蝕電流密度最低，合金的綜合性能最好，抗拉強度與伸長率分別達(dá)到245.8 MPa和16.2%，腐蝕速率為0.7235 mm/a。
關(guān)鍵字: 生物鎂合金；細(xì)晶強化；耐蝕性；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 of Henan Province, Luoyang 471023, China）
Abstract:The effects of hot extrusion process and annealing temperature on the microstructure and properties of Mg-Zn-Zr-Ce biomedical alloy were investigated by OM (Optical microscope), SEM (Scanning electron microscope), TEM (Transmission electron microscope), immersion test, electrochemical measures and tensile tests. The result shows that dynamic recrystallization occurs during hot plastic deformation, and the microstructure of extruded alloy is consisted of fine DRXed (Dynamic recrystallized) grain and unDRXed grain. The recrystallization occurs in deformed grains and the recrystallized grains grow subsequently after annealing treatment. When annealing temperature is over 200℃, the corrosion current (Jcorr) and grain size (d) meet the following equation: Jcorr=a+bd-1/2. According to the equation, it concludes that the alloy annealed at 200 ℃ for 3 h possesses the lowest corrosion current, and exhibits the optimized comprehensive properties. The elongation, tensile strength and corrosion rate are about 16.2%, 245.8 MPa and 0.7235 mm/a, respectively.
Key words: biomedical Mg alloy; grain refinement; corrosion resistance; mechanical property
