Improving corrosion and corrosion-fatigue resistance of AZ31B cast Mg alloy using combined cold spray and top coatings

Hypothesis: combined cold spray and e-paint top coatings improve corrosion and corrosion-fatigue of Mg alloys

Results:The combined coatings improved the corrosion resistance by a factor of 135, and significantly increased the fatigue life, with a fatigue strength of 80 MPa at 107 cycles, as compared to the as-cast sample. Surface topographic analysis of the corrosion-fatigue-tested samples demonstrated the presence of deep macro-pits on the cold sprayed AA7075 coating after 3.7 million cycles, while there were no such pits on the top coated samples, even after 107 cycles.

假设：结合冷喷涂与电子喷涂的顶层涂层能够提升镁合金的腐蚀及腐蚀疲劳性能。
结果：复合涂层显著提升了腐蚀抵抗力，其抗腐蚀能力提高了135倍，并大幅增加了疲劳寿命，在107次循环后，疲劳强度达到80 MPa，相较于铸造样品有显著提升。对腐蚀疲劳测试样品的表面形貌分析显示，在经过370万次循环后，冷喷涂的AA7075涂层上出现了深层的宏观凹坑，而在涂层上涂覆的样品中，即便在107次循环后，也未观察到此类凹坑。