(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: 采用金相顯微鏡(OM)、掃描電鏡(SEM)、透射電鏡(TEM)研究固溶處理溫度對Mg-2.0Zn-0.5Zr-3.0Gd(質(zhì)量分數(shù)，%)生物鎂合金顯微組織的影響，通過失重、析氫和電化學(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：鑄態(tài)合金中，第二相(Mg, Zn)3Gd在合金基體中呈網(wǎng)狀分布。固溶處理溫度在460~500 ℃時，合金的晶粒尺寸隨溫度的升高而逐漸增大，溫度為480 ℃時，沒有溶入基體的(Mg, Zn)3Gd相以顆粒狀或長條狀的形式存在于基體中，部分顆粒與α-Mg基體具有共格關(guān)系。隨著固溶處理溫度的升高，合金的腐蝕速率先減小后增大，固溶處理溫度在480 ℃時，合金的耐腐蝕性能比鑄態(tài)合金的有了較大的提高。在120 h的浸泡實驗中，合金的腐蝕速率在最后24 h時逐漸趨于穩(wěn)定。
關(guān)鍵字: 鎂合金；微觀組織；生物腐蝕性能；電化學(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 temperatures on microstructure of Mg-2.0Zn-0.5Zr-3.0Gd magnesium alloy were investigated by metallographic microscope (OM), scanning electronic microscope (SEM), transmission electron microscope (TEM). The corrosion properties of magnesium alloy were studied by mass loss, hydrogen evolution and electrochemical tests in the simulated body fluid (SBF). The results show that the second phase (Mg, Zn)3Gd is network distributed in the alloy matrix for the as-cast alloy. The grain size of alloy gradually increases with the increase of solid solution temperature at a temperature range of 460-500 ℃. There is no dissolved (Mg, Zn)3Gd phase present as a strip and particle form in alloy matrix when the temperature is 480 ℃. While partially granular phase has coherent interface relationship with α-Mg matrix. The corrosion rate for the solid solution alloy decreases with the increase of the solid solution temperature, and then increases. The corrosion resistance of the alloy is better than that of the as-cast alloy when the solid solution temperature is 480 ℃. In the immersion test of 120 h, the corrosion rate of alloys gradually reaches a steady state value in the last 24 h.
Key words: magnesium alloy; microstructure; biocorrosion property; electrochemical property
