3Y2Zn3。電化學(xué)測(cè)試結(jié)果表明，鑄態(tài)、擠壓370 ℃和擠壓390 ℃合金腐蝕電流密度分別為2.498、3.656、1.012 μA·cm-2。這是由于鑄態(tài)組織中析出相/金屬間化合物呈帶狀分布在基體中，可作為微陰極形成電偶腐蝕位點(diǎn)，加速合金腐蝕速率。合金在370 ℃擠壓時(shí)，由于實(shí)際溫度較低，部分粗化相未能充分溶解到α-Mg基體中，隨著析出相數(shù)量增加及分布混亂無序，微陰極面積比例增大，進(jìn)而導(dǎo)致腐蝕速率加劇。而390 ℃擠壓態(tài)鎂合金的擠壓速度快、耗散行為慢，且鑄錠與擠壓機(jī)間摩擦強(qiáng)烈，已發(fā)生充分動(dòng)態(tài)再結(jié)晶行為，降低了微陰極數(shù)量/面積，增強(qiáng)了合金耐腐蝕性能。;In order to ameliorate the microstructure characteristics and degradation behavior of the medical Mg alloys, the extrusion process was conducted to change the grain size characteristics and the distribution law of secondary precipitates/intermetallic compounds, and the microstructure characteristics and degradation behavior of as-extruded Mg-2Zn-0.5Gd-1Y-0.5Mn Mg alloy were analyzed. Results show that different hot-extrusion deformation methods do not change the types of the secondary phases in Mg-2Zn-0.5Gd-1Y-0.5Mn Mg alloy, but change their distribution and morphology. The main components of Mg-2Zn-0.5Gd-1Y-0.5Mn Mg alloy are α-Mg and W-Mg3Y2Zn3 phases. The electrochemical tests demonstrate that the corrosion current densities are 2.498, 3.656, and 1.012 μA·cm-2 for as-cast, extruded/370 °C, and extruded/390 °C Mg alloys, respectively. The precipitates/intermetallic com-pounds of strip shape are distributed in the matrix of as-cast Mg alloy, which can act as the micro-cathode, thus forming the galvanic-corrosion sites and accelerating the corrosion rates. Partial coarse precipitates cannot completely dissolve into the α-Mg matrix due to the low actual temperature of the Mg alloy during extrusion at 370 °C. With the disordered distribution and the increasing precipitates, the area proportion of micro-cathode is increased, which accelerates the corrosion rate. However, for the Mg alloy during extrusion at 390 °C, the extrusion speed is fast, the dissipation behavior is slow, and the friction between ingot and extruder is intense, indicating the occurrence of sufficient dynamic recrystallization, which reduces the number/area of micro-cathode and improves the corrosion resistance."/>