These properties are influenced by the melting and solidification phenomena caused by laser radiation. The demands pertaining to the quality of the finished parts include meeting standardized mechanical-property requirements, surface-roughness criteria, and accuracy. 26, 27 investigated keyhole formation and spattering using the ultra-high-speed synchrotron x-ray imaging. 24 have investigated the keyhole- and pore-formation phenomena using in-situ time-resolved X-ray imaging and diffraction analysis. Numerical simulations have also been performed in these extant studies. Other prior studies 19, 20, 21, 22 have investigated means to identify the melting and solidification phenomena by performing experiments involving the use of a test bench equipped with a 1-kW high-power single-mode fiber laser, high-speed camera, and thermo-viewer.
Efforts have been made to control the laser-radiation level by monitoring the melt-pool state parameters, such as its configuration and temperature 10. Extant studies have investigated the melt-pool behavior as well as the cause of the occurrence of defects, such as pores and lack of fusion, through not only experiments involving the use of a test bench and high-speed camera but also numerical simulations 10, 11, 12, 13, 14, 15, 16, 17, 18. Powder characteristics affect their recoating behavior, thereby influencing the melting and solidification phenomena caused by laser irradiation, which in turn, affect the quality of finished parts 6, 7, 8, 9. Thus, the demand to minimize the occurrence of defects during PBF processing and ensure high quality of finished parts has led to the development of monitoring and feedback control systems 4, 5.įor the development of the said system, it is important to elucidate the physical phenomena that occur during the laser-beam PBF (LB-PBF) process. Accordingly, the mechanical properties and surface roughness of PBF-manufactured parts are found to be inferior than those of wrought materials 1, 2. These concerns relate to the occurrence of such defects as pores and lack of fusion in the finished parts as well as the deterioration in surface roughness during processing owing to characteristics intrinsic to the PBF process 4, 5. However, several concerns have been raised regarding the quality of finished parts obtained using the PBF process. This process involves the use of a laser or an electron beam as the heat source 1, 2, 3.
Metal additive manufacturing (AM), especially powder-bed fusion (PBF), is considered an important process in the creation of new materials featuring exquisite material properties and complex structures. Therefore, in-situ monitoring of these areal surface-texture parameters can facilitate their use as control variables in the feedback system. In particular, the areal surface-texture parameters of reduced dale height, core height, root-mean-square height, and root-mean-square gradient demonstrate a strong correlation with specimen density. Using a statistical method, a strong correlation was observed between the areal surface-texture parameters and density or internal defects within specimens.
#PURE EDGE VIEWER ISO#
The density and 35 areal surface-texture parameters of manufactured specimens were determined based on the ISO 25,178–2 standard. In this study, 120 cubic specimens were fabricated via application of the LB-PBF process to the IN 718 Ni alloy powder. This study aims to investigate the correlation between the surface texture and internal defects or density of laser-beam powder-bed fusion (LB-PBF) parts. The availability of an in-situ monitoring and feedback control system during the implementation of metal additive manufacturing technology ensures that high-quality finished parts are manufactured.
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