Comparison of Substrate Preheating on Mechanical and Microstructural Properties of Hybrid Specimens Fabricated by Laser Metal Deposition 316 L with Different Wrought Steel Substrate

Abstract

The combination of additive manufacturing and conventional metal forming processes provides the possibility for improvements of forming efficiency and flexibility. Substrate preheating is an implementable technique to improve the interface adhesion properties of the hybrid forming method. The present experiment investigates the adhesion of additive manufactured 316 L steel on P20 and 1045 steel substrates under two substrate temperatures, and the geometrical characterization, interfacial microstructure and mechanical property of the hybrid specimens were compared. As a result, it was found that the ratio of deposition height to the width was reduced and the width was increased under substrate preheating. Tensile results show that the ultimate strength of 1045 and 316 L hybrid specimens was obviously increased, while the properties of hybrid specimens P20 and 316 L were similar, under different substrate temperature conditions. For the hybrid specimens with the metallurgically bonding characteristic, the tensile properties can reach the level of 316 L depositioned specimens fabricated by laser metal deposition (LMD). Furthermore, substrate preheating had little effect on the microstructure of the laser metal deposition zone, and significant influence on the microstructure of the heat affected zone, which was reflected in the difference of the hardness distribution.

Analysis of In Situ Optical Signals during Laser Metal Deposition of Aluminum Alloys

“…Deposition layers are formed after the solidification of the molten pool. The LMD process is highly sensitive to many processing parameters, including but not limited to laser power, laser scan speed and powder flow rate [2][3][4]. Aluminum alloys are of great interest in additive manufacturing due to their high specific strength and low density [5].…”

Effects of Deposition Strategy and Preheating Temperature on Thermo-Mechanical Characteristics of Inconel 718 Super-Alloy Deposited on AISI 1045 Substrate Using a DED Process

“…Soshi et al proposed a trochoidal deposition path to increase the preheating temperature of the substrate in a DED process [ 32 ]. Zhao et al examined the variation of the geometrical characterization, the interfacial microstructure and the mechanical property of specimens fabricated by a DED process using experiments [ 33 ]. They fabricated specimens through the deposition of AISI 316L steel on P20 and AISI 1045 steel substrates [ 33 ].…”

“…Zhao et al examined the variation of the geometrical characterization, the interfacial microstructure and the mechanical property of specimens fabricated by a DED process using experiments [ 33 ]. They fabricated specimens through the deposition of AISI 316L steel on P20 and AISI 1045 steel substrates [ 33 ]. In the fabrication of heterogeneous materials, defects and distortion frequently occur due to differences in thermal and mechanical properties between the deposited material and the substrate.…”