Optimization of Process Conditions for Additive Manufacturing Technology Combining High-Power Diode Laser and Hot Wire

Song Zhu,Motomichi Yamamoto,You Nakahara

doi:10.3390/met11101583

Abstract

A high-efficiency additive manufacturing technology that combines a high-power diode laser with a large-rectangle spot (beam width of 11 mm) and a hot-wire system was developed. The hot-wire system can generate Joule heat by wire current and heat a filler to its melting point independently from the main heat source of a high-power diode laser. A simple calculation method to derive the appropriate hot-wire current of Z3321-YS308L was proposed with verification by hot-wire feeding experiments without laser irradiation at various wire currents. The effect of process parameters, such as laser power, process speed, and the wire feeding rate (wire feeding speed/process speed) on bead characteristics was investigated by cross-sectional evaluations on three-layer depositions. High-speed imaging observations of wire melting and molten pool formation showed that the energy density input and the wire feeding rate were dominant parameters in terms of bead formation and hot-wire feeding stability. A 50-mm-high, 8-mm-wide, and 250-mm-long sample was fabricated by using appropriate process conditions, and tensile tests were performed by using a sub-sample from the large sample.

Highlights

Research, development, and practical application of additive manufacturing (AM)technologies, such as three-dimensional (3D) printing processes, have been carried out actively over recent years [1,2,3]
State-of-the-art studies have shown that metal-based AM technology can be categorized into three types according to the heat source: wire and arc additive manufacturing (WAAM), electron beam freeform fabrication (EBF3 ), and laser additive manufacturing (LAM) [11,12]
Wire and arc additive manufacturing has the advantages of a high fabrication efficiency, low equipment cost, large component manufacturing capability, and defect-forming prevention compared with other AM technologies, it has challenges, such as control of heat input, low cooling rates, large distortion, and surface fouling [13,14,15,16,17,18]

Summary

Introduction

Development, and practical application of additive manufacturing (AM)technologies, such as three-dimensional (3D) printing processes, have been carried out actively over recent years [1,2,3]. Compared with traditional subtractive manufacturing methodologies, AM technology yields continuous material accumulation by layer-by-layer addition and high-accuracy and complex 3D components through computer-controlled technology [4,5,6]. Development of the EBF3 method has been accelerated because of its ability to manufacture high-quality near-net-shape components with better mechanical properties and little material waste by using an electron beam as a heat source in a vacuum chamber. This method has problems, such as a low deposition rate, the requirement for a vacuum environment, and a high equipment price [12,21,22]

Results

Discussion

Conclusion