Heat Treatment Design for IN718 by Laser Metal Deposition with High Deposition Rates: Modeling, Simulation, and Experiments

Wire-based laser metal deposition enables to manufacture large-scale components with deposition rates significant higher compared to powder-based laser additive manufacturing techniques, which are currently working with deposition rates of only a few hundred gram per hour. However, the wire-based approach requires a significant amount of laser power in the range of several kilowatts instead of only a few hundred watts for powder-based processes. This excessive heat input during laser metal deposition can lead to process instabilities such as a non-uniform material deposition and to a limited processability, respectively. Although, numerous possibilities to monitor temperature evolution during processing exist, there is still a lack of knowledge regarding the relationship between temperature and geometric shape of the deposited structure. Due to changing cooling conditions with increasing distance to the substrate material, producing a wall-like structure results in varying heights of the individual tracks. This presents challenges for the deposition of high wall-like structures and limits the use of constant process parameters. In the present study, the temperature evolution during laser metal deposition of AA5087 using constant process parameters is investigated and a scheme for process parameter adaptions in order to reduce residual stress induced componential distortions is suggested.

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Influence of Process Conditions on the Local Solidification and Microstructure During Laser Metal Deposition of an Intermetallic TiAl Alloy (GE4822)

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06139-2 ◽

2021 ◽

Vol 52 (3) ◽

pp. 1106-1116

Author(s):

Silja-Katharina Rittinghaus ◽

Jonas Zielinski

Keyword(s):

Heat Treatment ◽

Additive Manufacturing ◽

Process Parameters ◽

Titanium Aluminides ◽

Metal Deposition ◽

Experimental Investigations ◽

Process Conditions ◽

Laser Metal Deposition ◽

Melt Pool ◽

Temperature Regimes

AbstractTemperature-time cycles are essential for the formation of microstructures and thus the mechanical properties of materials. In additive manufacturing, components undergo changing temperature regimes because of the track- and layer-wise build-up. Because of the high brittleness of titanium aluminides, preheating is used to prevent cracking. This also effects the thermal history. In the present study, local solidification conditions during the additive manufacturing process of Ti-48Al-2Cr-2Nb with laser metal deposition (LMD) are investigated by both simulation and experimental investigations. Dependencies of the build-up height, preheating temperatures, process parameters and effects on the resulting microstructure are considered, including the heat treatment. Solidification conditions are found to be dependent on the build height and thus actual preheating temperature, process parameters and location in the melt pool. Influences on both chemical composition and microstructure are observed. Resulting differences can almost be balanced through post heat treatment.

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Influence of solution heat treatment on microstructure and tensile properties of Inconel 718 formed by high-deposition-rate laser metal deposition

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2017.11.004 ◽

2018 ◽

Vol 740 ◽

pp. 389-399 ◽

Cited By ~ 17

Author(s):

Shang Sui ◽

Chongliang Zhong ◽

Jing Chen ◽

Andres Gasser ◽

Weidong Huang ◽

...

Keyword(s):

Heat Treatment ◽

Tensile Properties ◽

Deposition Rate ◽

Inconel 718 ◽

Solution Heat Treatment ◽

Metal Deposition ◽

High Deposition Rate ◽

Laser Metal Deposition

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Effect of post-heat treatment on the microstructure and mechanical properties of laser metal deposition Inconel 718

Journal of Mechanical Science and Technology ◽

10.1007/s12206-021-0610-4 ◽

2021 ◽

Author(s):

Pengfei Li ◽

Jianzhong Zhou ◽

Yadong Gong ◽

Xiankai Meng ◽

Jinzhong Lu

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Inconel 718 ◽

Metal Deposition ◽

Laser Metal Deposition ◽

Post Heat Treatment ◽

Microstructure And Mechanical Properties

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Laser Metal Deposition of Ti6Al4V—A Brief Review

Applied Sciences ◽

10.3390/app10030764 ◽

2020 ◽

Vol 10 (3) ◽

pp. 764 ◽

Cited By ~ 1

Author(s):

Chongliang Zhong ◽

Jianing Liu ◽

Tong Zhao ◽

Thomas Schopphoven ◽

Jinbao Fu ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

State Of The Art ◽

Metal Deposition ◽

Laser Metal Deposition ◽

Functional Coatings ◽

Laser Additive Manufacturing ◽

Research Directions ◽

Current State ◽

Main Emphasis

Laser metal deposition (LMD) is one of the most important laser additive manufacturing processes. It can be used to produce functional coatings, to repair damaged parts and to manufacture metal components. Ti6Al4V is one of the most commonly used titanium alloys, since it features a good balance of the mechanical properties of strength and ductility. The LMD of Ti6Al4V is attracting more and more attention from both science and engineering. The interest in processing Ti6Al4V with LMD in industry, especially in aerospace and medical branches, has been increasing in the last few years. In this paper, the state of the art for LMD of Ti6Al4V is reviewed. In the first part, the basics for Ti6Al4V, including, for example, the development history, the material properties, the applications, the crystal structure, the heat treatment and the mechanical properties, are introduced. In the second part, the main emphasis is on state of the art for LMD of Ti6Al4V. Initially, the process parameters of the current state of the art in the last years and their effects are summarized. After that, the typical microstructure after LMD is discussed. Then, the conducted heat treatment methods and the achievable mechanical properties are presented. In the end, some of the existing, current challenges are mentioned, and the possible research directions for the future are proposed.

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