Thermophysical Properties of Electric Arc Plasma and the Wire Melting Effect with Lanthanum and Sulfur Fluorides Addition in Wire Arc Additive Manufacturing

Sergey G Parshin,Peter Mayr

doi:10.3390/met11111756

Abstract

Achieving a higher quality in wire arc additive manufacturing (WAAM) is a result of the development of welding metallurgy, the development of filler wires, and the control of the thermophysical properties of the electric arc. In this paper, the authors developed composite wires for WAAM with a Ni-LaF3, Ni-LaB6 coating. The addition of LaF3, LaB6, and SF6 increases specific heat, thermal conductivity, enthalpy, and degree of plasma ionization, which leads to the increase in the transfer of heat from the arc plasma to the wire and to the change in the balance of forces during wire melting. The increase in the Lorentz electromagnetic force and the decrease in the surface tension force made it possible to reduce the droplet diameter and the number of short circuits during wire melting. The change in the thermophysical properties of the plasma and droplet transfer with the addition of LaF3, LaB6, and SF6 made it possible to increase the welding current, penetration depth, accuracy of the geometric dimensions of products in WAAM, reduce the wall thickness of products, and refine the microstructure of the weld metal using G3Si1, 316L, AlMg5Mn1Ti, and CuCr0.7 wires.

Highlights

Wire arc additive manufacturing (WAAM) is an advanced technology for increasing productivity and reducing costs in the manufacturing of products of steels and alloys [1,2].WAAM is used to create advanced bionic design products in the car manufacturing, mechanical engineering, and shipbuilding industries including the production of aircraft and rocket engine components
The aim of the study is to change the thermophysical properties of an electric arc plasma, droplet transfer and products formation in WAAM by introducing lanthanum fluoride LaF3, lanthanum boride LaB6, sulfur hexafluoride SF6 into argon using wires of
When fluoride LaF3 and boride LaB6 are added into the plasma of an electric arc, evaporation, dissociation, and ionization occur according to the endothermic reactions

Summary

Introduction

Wire arc additive manufacturing (WAAM) is an advanced technology for increasing productivity and reducing costs in the manufacturing of products of steels and alloys [1,2].WAAM is used to create advanced bionic design products in the car manufacturing, mechanical engineering, and shipbuilding industries including the production of aircraft and rocket engine components. Wire arc additive manufacturing (WAAM) is an advanced technology for increasing productivity and reducing costs in the manufacturing of products of steels and alloys [1,2]. The development of WAAM is hindered by the problems with product quality and reliability due to the sensitivity of steels and alloys to the thermal cycle and metallurgical problems of weldability [3]. An analysis of publications related to WAAM reveals that most of the research in this field is conducted in order to improve quality and productivity.

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