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利用消失模铸造技术,对镁合金铸件表面进行复合改性研究。选用金属铝粉作为合金化主要元素,PbO-ZnO-Na2O系低温玻璃粉为陶瓷化材料。选择真空度大小为-0.06 MPa,温度为800℃进行浇注。结果表明,在镁合金铸件表面获得了一定厚度的复合层。显微硬度测试表明,从表面至基体复合层的硬度呈梯状分布,硬度值的变化与单一的陶瓷层相比有一个过渡区,有利于提高表面陶瓷层与基体的界面结合质量。经过表面复合改性后,镁合金铸件的腐蚀电位提升了400 mV,腐蚀电流下降了3个数量级,镁合金的耐蚀性得到了大幅度提高。
Using the technology of lost foam casting, the surface modification of magnesium alloy was studied. Select the metal aluminum as the main alloying elements, PbO-ZnO-Na2O-based low-temperature glass powder ceramic materials. Select the size of the vacuum is -0.06 MPa, the temperature is 800 ℃ for casting. The results show that a certain thickness of composite layer is obtained on the surface of magnesium alloy castings. Microhardness tests show that the hardness of the composite layer from the surface to the matrix is distributed in a ladder shape, and the change of the hardness value has a transition zone compared with the single ceramic layer, which is beneficial to improve the interface bonding quality of the surface ceramic layer and the substrate. After surface modification, the corrosion potential of magnesium alloy castings increased by 400 mV, the corrosion current decreased by 3 orders of magnitude, and the corrosion resistance of magnesium alloy was greatly improved.