Preparation Of Amorphous Inoculant And Its Effect On The Microstructure And Mechanical Properties Of 6061 Aluminum Alloy

6xxx Al-Mg-Si aluminum alloy is widely used as structural components,such as automotive body sheets and aerospace applications,because of its excellent processability,weld ability and good corrosion resistance.The technique of room temperature rolling and following aging treatment is used to improve the mechanical properties of Al 6061 alloy.However,after room temperature rolling,initial coarse grains is replaced by coarse elongated grains resulting in the reduction of mechanical properties.Thus,in this academic dissertation,two different kinds of amorphous inoculants were prepared to refine and modify the initial coarse grain and the characterization of amorphous inoculant and the mechanism of refinement were also studied in detail.Amorphous ZrCuAl and AlNiYCe alloys were successfully prepared by vacuum rapid solidification technique according to the thermodynamic law.Different contents of amorphous ZrCuAl and AlNiYCe ribbons were added to aluminum 6061 alloy.The smallest grain of the inoculated aluminum 6061 alloy was got with addition of 0.3 wt.% ZrCuAl or 0.4 wt.%AlNiYCe amorphous ribbons,respectively.It can be seen that their initial grains have been replaced by elongated grains indicating the rolling has strong influence on the microstructure.The lamella spacing of inoculated RTR aluminum 6061 alloy decreases in the vertical direction and the remaining long fibrous grains are fragmented and reduced in thickness with addition of ZrCuAl or AlNiYCe amorphous alloy.The mechanical properties of inoculated RTR 6061 aluminum alloy before and after aging including vickers hardness,tensile strength,yield strength and elongation have been significantly improved.The vickers hardness,tensile strength,yield strength and elongation of RTR aluminum 6061 alloy inoculated by 0.2 wt.% amorphous ZrCuAl ribbons and after aging were 118.3?3.4 HV,358 MPa,346 MPa and 8.9%,respectively.The vickers hardness,tensile strength,yield strength and elongation of RTR aluminum 6061 alloy inoculated by 0.4 wt.% amorphous AlNiYCe ribbons and after aging were 123.8?1.5 HV,375 MPa,360 MP and10.8%,respectively.This study provides a cost-effective and high-efficiency processing technique of refinement for room temperature rolled Al 6061 alloy.Moreover,the refinement and reinforcement mechanism of the 6061 aluminum alloy were studied in detail.