Research on the forming process of three-dimensional metal parts fabricated by laser direct metal forming

An overview of Direct Laser Deposition for additive manufacturing; Part I: Transport phenomena, modeling and diagnostics

“…For such parallel-line scanning, the deposition head must accelerate or decelerate at the beginning and end of each deposition trail (or trace), respectively. For constant laser power and powder feed rate, this results in an observable phenomena known as a 'step effect' which becomes more prominent with layer number [42,153]. Basically, the trace will have a hump, or nodulation, at its start and end.…”

“…Like PBF-L, the finished part(s) must be sheared off from the substrate after the AM process. DLD can be utilized for additive manufacture of a variety of metals and even ceramics -including: Inconel 625, stainless steels, H13 tool steel, titanium alloy, chromium, tungsten and more [35,[39][40][41][42][43][44][45]. Direct Laser Deposition has also been utilized to successfully manufacture cerments composed of tungsten carbide-cobalt [46].…”

“…This will control the imposed heat flux at the deposition layer interface. Pi et al found that the crosssectional morphology (build height/profile) of AISI 316 SS (single nozzle) depends strongly on the scan width[42]. Keeping the laser power constant, while decreasing the scan width, results in a single-line morphology with an arc-shaped top, and this arc becomes more exaggerated with subsequent deposition layers.…”

Effects of Carbon and Boron on Structure and Properties of Austenitic Stainless Steel Coatings Fabricated by Laser Remanufacturing

“…Great effort has been devoted to date to improving mechanical properties of materials by optimizing parameters of the laser metal manufacturing process. However, there are still defects observed in the coatings, such as pores, slag inclusion, deformation and high residual tensile stress, thereby limiting their widespread applications . The Ni–Cr–B–Si alloys have been widely used because boron and silica are strong reductants which can suppress metal oxides in molten pool while forming borosilicate possessing low density, low melting point, and high liquidity.…”

Management of Total Entrepreneurial Activity by Adaptive Neuro-Fuzzy Technique

“…In work [6], two different irradiating schemes were used and compared for flame forming of a bowl-shaped surface and it was proved that the obtained bowl-shaped surface with spiral irradiating scheme has larger curvatures and symmetry and lower residual stresses in comparison with the obtained bowl-shaped surface with combined irradiating scheme. To improve the forming quality of parts fabricated by laser direct metal forming, the forming process of three-dimensional parts under open-loop LDMF system was studied in paper [7] and it was suggested that uneven surface of parts was caused by instability of process parameters. Laser forming is a thermal forming process, which uses laser beam irradiation to produce desired final forms.…”