Study On Bulk Nano-aluminum Prepared By Explosion Sintering Technology And Mechanical Properties Effects

In recent years,there have been a lot of serious accidents caused by the failure of material properties,and the block aluminum prepared by traditional technology is difficult to meet people's pursuit of high mechanical properties.Therefore,it is necessary to enhance the mechanical properties of materials to improve the intrinsic safety of facilities during the use of it.The bulk aluminum with high mechanical properties was prepared by explosive sintering in this paper.The mechanical properties of the aluminum were characterized by a series of tests,such as microhardness test,compressive strength test and density test.The phase and microstructure of the aluminum were characterized by XRD,metallographic microscope and SEM.Firstly,the mechanical properties and microstructure of aluminum materials were compared and analyzed by systematically studying the influence factors on the explosive sintering device,such as the thickness of inner casing,the thickness of explosive layer,the height of explosive charge and the depth of pressure relief hole,etc.Under the conditions of 2mm inner casing wall thickness,12.2 mm explosive layer thickness,260 mm explosive loading height and 13 mm pressure relief hole depth,the forming effect and mechanical properties of the bulk aluminum prepared by explosive sintering are the best.Secondly,through the systematic study on the influence factors of the characteristic parameters of aluminum powder,such as the initial loading density of aluminum powder,the diameter of aluminum powder and the mixing ratio of nano-aluminum powder,the differences of mechanical properties and microstructure of aluminum materials are compared and analyzed.Under the condition that the initial packing density of aluminum powder is above 50%,the forming effect of aluminum is better,and the mechanical properties of the bulk aluminum prepared by explosive sintering are the best under the condition that the mixing ratio of nanoaluminum powder is 100%.At last,the comprehensive evaluation method and analytic hierarchy process(AHP)was combined in this paper.Through establishing the evaluation index set,establishing the evaluation standard,establishing the membership matrix R,determining the weight coefficient of each index,the influence factors of explosive sintering of bulk aluminum were evaluated by the mathematical model of the mold and the quantitative optimization of different relief pore depth and mixing ratio of nano-aluminum powder.The results show that the comprehensive mechanical properties of bulk aluminum prepared with 13 mm relief pore depth are better,and those of bulk aluminum prepared by pure nano-aluminum powder are better.