Arc Additive Manufacturing Shape Control Of 2319 Aluminum Alloy Rocket Transition Frame

The aluminum alloy transition end frame is the main load-bearing member of the grading rocket transition section,which is used to realize the connection between the rocket stage and the stage,and plays an important role in the rocket launch process.At present,the transitional end parts are mainly produced by machining forging blanks,The production efficiency is low and the production cost is high,which has been unable to meet the high frequency and various types of use requirements of China’s carrier rockets.Arc additive manufacturing is a new type of manufacturing method that uses electric arc as a heat source.It has a series of advantages such as high efficiency and low cost.It can well meet the manufacture of metal parts with large sizes and complex structures.Great progress has been made in aerospace and other fields.This article mainly research on "shape control" of 2139 aluminum alloy wire using arc additive manufacturing,and prints out the transition unit element members with qualified dimensions.Before printing the transitional end frame,it is necessary to print out the transitional end unit body structure that meets the size requirements.First,the forming size and quality of single-layer single-pass and single-layer multi-pass under different processes are studied.When the single-layer single-pass stacking is performed within the range of 80-150 A,as the current increases,and the melting width of the stacked metal gradually increases,and the remaining height has a small dimensional change and remains at 3.5mm,and near the maximum at 120 A.The mathematical model formula of single-layer multi-layer stacked metal layer height was established by using the quadratic regression universal rotation combination design method,in which the current was positively correlated,and the gun head moving speed and offset were negatively correlated.The influence on the layer height It is the gun head moving speed> offset> current.According to the obtained layer height mathematical model,select a reasonable stacking layer height,use the corresponding process parameters to print the structure of the transition end unit body,and use three-dimensional measurement technology to detect the size error within ±1.983 mm,with sufficient machining allowance to meet the size Claim.According to the structural characteristics of the unit body,the effects of different slicing processes and scanning paths on the deformation of the substrate and components were studied,and the processes and paths with small deformations were selected through comparative experiments.(1)When printing rectangular metal blocks of the same size and a height of 20 mm,choose three printing methods with a layer height of 3.33 mm,4mm,and 5mm.When the stacking method with a slice layer height of 5mm is found,the deformation of the substrate is the smallest,which is3.1776.mm;(2)When printing a ring-shaped member,compared with the inside-out scanning method,the overall deformation of the substrate from the outside-to-in scanning method is smaller.But the outside to inside scanning method causes a larger amount of deformation at the corners near the arc extinction point,causing the overall substrate is deformed unevenly.(3)In the scanning method of the reinforcing plate part,the number of arc offset scans of the contour offset scan is large,resulting in a large amount of substrate deformation.And this method has many corners when printing,resulting in poor print quality.Therefore,it is more reasonable to print the part using the arc scanning method when printing.Print the unit body using the process and path with the least amount of deformation,and the overall deformation is less than 0.9mm.Finally,the aluminum alloy transition end frame member is printed,and partition printing is performed according to the structural characteristics of the member.Using three-dimensional measuring equipment and processing software Geomagic Qualify to measure the size of each printing area.The overall error of the aluminum alloy component is measured within ±2.1268 mm,which meets the requirements of parts processing and use.