Effect of Silver on Mechanical and Wear Properties of Cast Al-Cu-Mg Alloy

To study the effect of Ag element on the microstructure and properties of Al-Cu-Mg alloys, several Al-Cu-Mg alloys with different Ag contents were investigated in this paper. The mechanical properties of the alloys were studied through hardness tests, tensile tests, and friction and wear tests. The microstructure of the alloy was observed by scanning electron microscope, laser confocal microscope, optical microscope, and transmission electron microscope. The results show that by adding Ag element to Al-Cu-Mg alloy, the fine omega phases with high density precipitated inside the alloy can effectively enhance the properties of the alloy. When the addition of Ag element is 0.2 wt.%, the omega phases inside the alloy are fine and evenly distributed, the hardness and strength of the alloy are greatly improved, the depth of friction and wear is significantly reduced, and the comprehensive mechanical properties are effectively improved. The hardness and ultimate tensile strength of the alloy are 140.4 HV and 370 MPa, respectively. The friction and wear coefficient of the alloy is 2.304.