Quantitative investigation of thermal evolution and graphitisation of diamond abrasives in powder bed fusion-laser beam of metal-matrix diamond composites

Ma, Qingyuan; Peng, Yujia; Chen, Yongqian; Gao, Yuan; Zhang, Shanghua; Wu, Xiaojuan; Zheng, Jun; Wu, Hong; Huang, Lan; Liu, Yong; Zhang, Wei

doi:10.1080/17452759.2022.2121224

Cited by 12 publications

(7 citation statements)

References 29 publications

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“…Thus, thermal damage to the diamond primarily stems from heat transfer originating from the molten pool, while the direct energy transfer from the laser to the diamond assumes a subordinate role. In addition, the lowest ablation threshold of the diamond is approximately 1.21 × 10 7 W/cm 2 under direct laser irradiation at a wavelength of 1064 nm, and the maximum equivalent laser flux in this experiment is 4.3 × 10 6 W/cm 2 , which is much lower than the diamond ablation threshold, which further proves the significance of the influence of heat transfer in the molten pool on the temperature of the diamond [ 13 ].…”

Section: Resultsmentioning

confidence: 63%

“…In this paper, the Gaussian heat source model was used in the simulation, and the radius of the Gaussian spot in this paper is defined by the "1/e 2 energy method". Based on this assumption, the expressions of the Gaussian surface heat source model can be described as [13,14]:…”

Section: Governing Equationsmentioning

confidence: 99%

“…In addition, the lowest ablation threshold of the diamond is approximately 1.21 × 10 7 W/cm 2 under direct laser irradiation at a wavelength of 1064 nm, and the maximum equivalent laser flux in this experiment is 4.3 × 10 6 W/cm 2 , which is much lower than the diamond ablation Combining with Models I and II, the temperature distribution cloud of the diamond in the molten pool is studied. In our previous work [13], the process of diamond temperature variation in the molten pool is divided into three stages, which have been further refined in this paper. The specific movement of the molten pool and the corresponding diamond temperature variation can be divided into eight stages as shown in Figure 7.…”

Section: Thermodynamics Of the Diamondmentioning

confidence: 99%

“…In this paper, the Gaussian heat source model was used in the simulation, and the radius of the Gaussian spot in this paper is defined by the “1/e 2 energy method”. Based on this assumption, the expressions of the Gaussian surface heat source model can be described as [ 13 , 14 ]:

where P is the average power of the laser, r 0 is the radius of the laser beam, η is the absorption rate, and v is laser scan velocity.…”

Section: Numerical Simulation Model Of Lpbf Processmentioning

confidence: 99%

“…By combining simulation results and the diamond graphitization phenomenon, we successfully replicated the thermal damage process of diamond abrasives in the Powder Bed Fusion-Laser Beam (PBF-LB) process and experimentally verified the temperature threshold for thermal damage transformation. Furthermore, a quantitative relationship model, “PBF-LB process-abrasive temperature-graphitization degree-mechanical performance”, was established [ 13 ]. In this paper, we delve deeper into the thermodynamic behavior of diamonds within the molten pool.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Simulation of Temperature Characteristics and Graphitization Mechanism of Diamond in Laser Powder Bed Fusion

Chen,

Zhang,

Liu

et al. 2023

Materials

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Thermal damage to diamonds is a major limitation in laser powder bed fusion (LPBF) processing of metal matrix diamond composites. In this paper, a numerical simulation model was established to describe the thermal effect of the Diamond-CuSn10 composite on the LPBF process. The simulation results show that the temperature of the diamond presents a double-peak structure, and the double-peak temperature curve shape can be modulated by modifying the laser scanning offset and the size of the diamond powder. And it suggests that the heat of the diamond mainly comes from the transfer of the molten pool. Then, combined with the experimental phenomenon, the mechanism of diamond graphitization in the LPBF process is analyzed. It indicates that since the surface defects of the diamond inhibit the heat conduction of the diamond, the temperature accumulates on the surface, leading to the graphitization of the diamond. Finally, based on this model, the potential of Ti-coated diamonds to prevent and reduce thermal damage in the LPBF process has been extensively studied. It is found that a Ti coating with low thermal conductivity can effectively reduce diamond temperature and improve diamond graphitization resistance. This study can provide a good method and basis for the preliminary selection of LPBF process parameters and the understanding of the graphitization mechanism of diamond tools.

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Section: Resultsmentioning

confidence: 63%

Section: Governing Equationsmentioning

confidence: 99%

Section: Thermodynamics Of the Diamondmentioning

confidence: 99%

where P is the average power of the laser, r 0 is the radius of the laser beam, η is the absorption rate, and v is laser scan velocity.…”

Section: Numerical Simulation Model Of Lpbf Processmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%