Simulation Of Angular Extrusion Forming Of Box-shaped Components With High Zinc Aluminum Alloy Containing Scandium

Box-shaped component is the key component of large data storage host and portable hard disk on deep space and deep sea detector equipment.The traditional manufacturing process of the box body is mechanical cutting or die casting,with serious material waste and low service performance.Under the conditions of large storage and long-term operation,the shell is seriously heated.With the development of information technology,higher requirements are put forward for high-performance manufacturing of large capacity box-shaped components,especially to meet performance requirements such as high strength,high damping,and high ductility.This article takes Sc containing high zinc aluminum alloys(Al-Zn-Sc and Al-Zn-Mg-Sc)as the research object,conducts hot compression experiments on the two alloys,and establishes a thermal deformation constitutive model.Simulate the angular extrusion forming process of Al-Zn-Sc and Al-Zn-Mg-Sc alloy boxshaped components under different process parameters(extrusion speed,friction coefficient,initial temperature),and optimize the optimal process parameters.The main conclusions are as follows:(1)The hot compression tests of Al-Zn-Sc and Al-Zn-Mg-Sc alloys were carried out on Gleeble-3500 thermal simulation testing machine,and the constitutive models were established.As the true strain increases,the true stress sharply increases to a peak value and then decreases to a steady state.The true stress decreases as the deformation temperature increases and the strain rate decreases.By means of metallographic and electron backscatter diffraction technique,it is found that the softening mechanism of Al-Zn-Sc and Al-Zn-Mg-Sc alloys is closely related to deformation temperature and strain rate.With the increase of deformation temperature and the decrease of strain rate,a large number of subgrains containing small angle grain boundaries are transformed into recrystallized grains containing large angle grain boundaries.The main softening mechanism also changes from dynamic recovery to dynamic recrystallization.(2)Using Deform-3D software to study extrusion speed,friction coefficient,and initial temperature,numerical simulation and analysis of Sc containing high zinc aluminum alloy boxshaped components were conducted.The results show that the maximum damage value of boxshaped components presents a trend of increasing first and then decreasing,and the strain value presents a continuous increasing trend with the increase of deformation degree.After the extrusion is completed,the damage value on the inner surface of the box-shaped component is the largest,followed by the middle part,and the outer surface is the smallest.The damage value shows an increasing trend in the height direction(from the bottom to the end face).The equivalent strain value on the inner surface of the box-shaped component is higher than that on the outer surface.The equivalent strain value at the bottom is higher than that at the end face.(3)Simulation study on angular extrusion of Al-Zn-Sc and Al-Zn-Mg-Sc box-shaped components.It was found that when the extrusion speed increased from 0.5mm/s to 1.3mm/s,the maximum damage value of Al-Zn-Sc and Al-Zn-Mg-Sc box-shaped components decreased by 42%and 68.5%,respectively.The uniformity of equivalent strain increased by 25.1% and 48%.When the friction coefficient increases from 0.1 to 0.2,the maximum damage value of Al-Zn-Sc and Al-ZnMg-Sc box-shaped components increases by 147% and 197%,respectively.The uniformity of equivalent strain decreased by 33% and 76.8%.When the initial temperature increases from 360 ℃to 450 ℃,the maximum damage value of Al-Zn-Sc and Al-Zn-Mg-Sc box-shaped components decreases by 63.6% and 73.7%,respectively.The uniformity of equivalent strain increased by 17.6%and 37%.Under the optimal forming process conditions,the maximum damage value of Al-Zn-MgSc alloy box-shaped components decreased by 30.7% compared to Al-Zn-Sc box-shaped components.Improved uniformity by 30.1% due to equivalent strain.(4)The results indicate that,the angular extrusion forming of Al-Zn-Mg-Sc alloy box-shaped components is found to be best at the conditions of the extrusion speed of 1.3 mm/s,the friction coefficient of 0.1,and the initial temperature of 450℃.