Investigations on laser powder bed fusion of tungsten heavy alloys

Schwanekamp, Tobias; Müller, Andréas; Reuber, Martin; Gobran, Hany; Gdoura, Nabil; Cetto, Sebastian von

doi:10.1016/j.ijrmhm.2022.105959

Cited by 2 publications

(1 citation statement)

References 11 publications

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“…This phenomenon is attributed to the fact that at lower energy densities, the temperature of the melt pool is low, resulting in more unfused flaws in the sample, and slow gas escapes, leading to fewer gas pores. As the energy density increases, the temperature of the melt pool rises, prolonging the presence of the melt pool and increasing the time for gas escape, thereby reducing the unfused flaws and gas pores [19,20]. However, excessively high energy density can result in keyholes, spatters, and spheroidization as well [21].…”

Section: Relative Density Of the High-nitrogen Steelmentioning

confidence: 99%

Process Parameter Optimization for Selective Laser-Melted High-Nitrogen Steel and the Effects on Microstructure and Properties

Sun

Ren

Wang

et al. 2023

Metals

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Chromium nitride powder is blended with pre-alloyed powder to make an overmatched powder with a high nitrogen concentration in order to manufacture high-nitrogen steel by selective laser melting. By employing a wider range of process parameters, the impact of process parameters on the relative density, nitrogen concentration, microstructure, and mechanical properties of high-nitrogen steel is investigated. In simulated human body fluid conditions, the corrosion resistance of high-nitrogen steel, pure titanium, and 316L was compared and evaluated. The findings demonstrate that the relative density of high-nitrogen steel initially rises and then falls with the increase in energy density, reaching a high value of 98.8% at 148.8 J/mm3. With rising energy density, the nitrogen concentration falls. The microstructure of high-nitrogen steel is mainly composed of columnar and cellular grains. Both grain sizes steadily grow, but their mechanical characteristics initially rise and then fall as the energy density rises from 83.3 to 187.3 J/mm3. With yield strength, tensile strength, and elongation reaching 921.9 MPa, 1205.1 MPa, and 27%, respectively, the alloy exhibits outstanding mechanical characteristics when the laser power is 250 W, the scanning speed is 700 mm/s, and the associated energy density is 148.8 J/cm3. The high-nitrogen steel at an energy density of 148.8 J/mm3 has the lowest corrosion rate when compared to pure titanium and 316L steel, which suggests that the HNS alloy will have good corrosion resistance in human body fluid conditions.

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Section: Relative Density Of the High-nitrogen Steelmentioning

confidence: 99%

Process Parameter Optimization for Selective Laser-Melted High-Nitrogen Steel and the Effects on Microstructure and Properties

Sun

Ren

Wang

et al. 2023

Metals

View full text Add to dashboard Cite

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Laser Beam Machining of Tungsten Alloy: Experimental and Numerical Analysis

Begić-Hajdarević

Bijelonja

2022

Metals

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Laser beam machining of various materials has found wide applications in the industry due to its advantages of high-speed machining, no tool wear and no vibration, precision and accuracy, low cost of machining, etc. Investigations into the laser beam machining of uncommon alloy are still limited and more research is needed in this field. In this paper, an analysis of the laser beam machining of tungsten alloy was performed, for cutting and drilling machining processes. First, an experimental analysis of microhardness and microstructure on the laser-cut samples was performed, and then the numerical simulation of the laser beam drilling process and its experimental validation was carried out. The experiments were carried out on a tungsten alloy plate of two different thicknesses, 0.5 and 1 mm. No significant changes in the microhardness, nor in the microstructure characteristics in the heat-affected zone (HAZ), were observed for the cutting conditions considered. A two-dimensional axisymmetric mathematical model for the simulation of the laser beam drilling process is solved by a finite volume method. The model was validated by comparing numerical and experimental results in terms of the size of HAZ and the size and shape of the drilled hole. Experimental and numerical results showed that HAZ is larger in the 0.5-mm-thick plate than in the 1-mm-thick plate under the same drilling conditions. Good agreement was observed between the experimental and numerical results. The developed model improves the understanding of the physical phenomena of laser beam machining and allows the optimization of laser and process parameters.

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Investigations on laser powder bed fusion of tungsten heavy alloys

Cited by 2 publications

References 11 publications

Process Parameter Optimization for Selective Laser-Melted High-Nitrogen Steel and the Effects on Microstructure and Properties

Process Parameter Optimization for Selective Laser-Melted High-Nitrogen Steel and the Effects on Microstructure and Properties

Laser Beam Machining of Tungsten Alloy: Experimental and Numerical Analysis

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