Effect of External Magnetic Field on the Forming, Microstructure and Property of TC4 Titanium Alloy during the Directed Energy Deposition Arc Additive Manufacturing

Abstract

In this work, the thin wall components of TC4 titanium alloy were produced by using external magnetic field hybrid gas metal welding (EM-GMAW). The effect of the external magnetic field on the forming, microstructure, and property of wire arc additively manufactured TC4 titanium alloy was studied in detail. The results showed that the height of the average deposition layer of EM-GMAW was less than that of GMAW and decreased with the increase of magnetic excitation current, and the width of the average deposition layer of EM-GMAW was greater than that of GMAW. The microstructure of the deposition layer consisted of fine α phase and coarse β grains. Compared with the traditional GMAW, the coarse β grain size in the EM-GMAW was reduced obviously. The maximum size of β grain was decreased by 100μm when the magnetic excitation current of 3A was used. In addition, the EM-GMAW tensile strength in the transverse and horizontal was increased by around 20 MPa and 100 MPa, respectively, compared with that of GMAW.