中文摘要：

采用环保型化学转化工艺，利用扫描电镜、X射线衍射和全浸蚀等分析试验手段，研究了AZ91D镁合金锡酸盐化学转化膜的形貌、相结构及耐腐蚀性。结果表明，转化膜主要由镁的仅相、B相和MgSnO3·3H2O组成；该环保型化学转化工艺可获得由近球状微粒构成的银白色膜层，表面均匀平整。该膜层的耐蚀性能优于传统含铬DOW7工艺形成的防护膜，且所用成膜液无铬，符合环保要求。

英文摘要：

The surface morphologies, phase structures and corrosion resistance of the stannate conversion coating on AZ91D magnesium alloy gained from an environment-friendly conversion process were investigated by using SEM ,XRD and salt immersion test. The results show that the conversion coating consisted of α phase, β phase and MgSnO3·3H2O. The silvery white coating composed of sphere-like particle layer formed uniform right on the under layer, with uniformand level surface. The environment-friendly chromium-free process was more effective to improve the corrosion resistance of magnesium alloys than that of the traditional DOW7 process.