(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: 通過金相顯微分析(OM)、掃描電鏡觀察(SEM)、透射電鏡觀察(TEM)和拉伸性能測試研究不同時(shí)效時(shí)間對Mg-2.0Zn-0.5Zr-3.0Gd生物鎂合金顯微組織及力學(xué)性能的影響，通過質(zhì)量損失和電化學(xué)方法研究合金在模擬體液(SBF)中的耐腐蝕性能。結(jié)果表明：時(shí)效時(shí)間為4~20 h時(shí)，合金中析出相的尺寸及數(shù)量隨時(shí)效時(shí)間的延長而增加，析出相主要以納米級棒狀和顆粒狀的(Mg, Zn)3Gd相形式存在，部分棒狀析出相與α-Mg基體具有共格界面關(guān)系。合金的強(qiáng)度及伸長率隨時(shí)效時(shí)間的延長先升高后降低。在120 h的浸泡實(shí)驗(yàn)中，合金的平均腐蝕速率、點(diǎn)蝕孔洞的數(shù)量及孔洞尺寸隨時(shí)效時(shí)間的延長而逐漸增大，腐蝕速率隨浸泡時(shí)間延長呈現(xiàn)出先減小、后增大、再緩慢減小以及最后趨于穩(wěn)定的過程。
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:The effects of aging time on the microstructure and mechanical properties of Mg-2.0Zn-0.5Zr-3.0Gd biomedical magnesium alloy were investigated by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and tensile properties tests. The results show that the size and quantity of precipitated phases in the alloy increase with the increase of aging time at range of 4-20 h. The precipitated phases are mainly in the form of nano-sized rod-like and granular (Mg, Zn)3Gd phase. While partially rod-like precipitated phase has coherent interface relationship with α-Mg matrix. The strength and elongation of the alloy gradually increase with the increasing of the aging time, and then decrease. In the 120 h immersion experiment, the average corrosion rates, number and size of corrosion holes in the alloy increased with increase of the aging time. The corrosion rate decreases at first, then increase, and then decrease slowly. At last, it tends to be stable with the increase of immersion time.
Key words: magnesium alloys; microstructure; biocorrosion properties; mechanical properties
