Power Spinning of the Curved Head with Tailor Welded Aluminum Alloy Blank: Deformation, Microstructure, and Property

Fei Ma,Pengyu Ma,Mei Zhan,Pengfei Gao

doi:10.3390/met9121359

Abstract

The power spinning of tailor-welded blank (TWB) provides a feasible way to form the large-scale curved heads of aluminum alloy. However, the inhomogeneous material property of TWB produces different and more complex spinning behaviors compared with the traditional spinning of an integral homogenous blank. In this research, the deformation characteristics, microstructure, and the properties of the power spun curved head with aluminum alloy TWB were studied. A finite element model considering the inhomogeneous material property of welded blank is developed for the analysis of the power spinning process. To conduct accurate and efficient simulation, an effective meshing method is proposed according to the feature of TWB. The simulation and experimental results show that the weld zone (WZ) presents the larger equivalent stress but smaller equivalent strain than base material zone (BMZ) in power spinning due to its larger deformation resistance. Under the combined effects of the spiral local loading path and inhomogeneous deformability of TWB, the equivalent strain near the weld zone has an asymmetric V-shaped distribution. Strain inhomogeneity gradually increases with deformation and leads to an increase of the flange swing degree. In addition, the circumferential thickness distribution is relatively uniform, which is little affected by the existence of the weld line. However, the circumferential unfitability distribution becomes non-uniform and the roundness is worsened due to the existence of the weld line. Compared to the initial blank, the microstructure in WZ and BMZ are both elongated after spinning. The tensile strength is improved but plasticity reduced after power spinning based on the circumferential and radial tests of WZ and BMZ. The results are of theoretical and technical guidance for the power spinning of the curved head component with TWB.

Highlights

The surface heads of aluminum alloy are widely used as a key component for pressure vessels in the aerospace field to satisfy the high demand for performance, as they are lightweight, and are low cost
Both of equivalent stress homogeneous workpieces present a very close distribution feature in base material zone (BMZ). Both of equivalent stress and strain present the annular distribution feature. They both increase with the radial and strain present the annular distribution feature
They both increase with the radial direction and reach the maximum in the annular zone behind roller. These features are the same as direction and reach the maximum in the annular zone behind roller. These features are the same as those in the common power spinning of the curved head, which have been explained in reference [10]

Summary

Introduction

The surface heads of aluminum alloy are widely used as a key component for pressure vessels in the aerospace field to satisfy the high demand for performance, as they are lightweight, and are low cost. These components are usually formed by spinning technology, which has the advantages of low forming load, simple tooling, and high efficiency [1,2]. It is difficult to obtain a high-quality integral blank with a large size in this order by rolling directly. This limits the Metals 2019, 9, 1359; doi:10.3390/met9121359 www.mdpi.com/journal/metals

Methods

Discussion

Conclusion