Effect of Heat Treatment on Hardness of Co-Cr-Mo Alloy Deposited With Laser Engineered Net Shaping

Corrosion of metallic materials fabricated by selective laser melting

“…The laser energy density for the lowest porosity (~0.3%) of the SLMed 316L stainless steel was around 105 J/mm 3 in Fig. 2a 75 ; for the SLMed AZ91D magnesium alloy, the process window for the highest relative density was in the range from 83 to 167 J/mm 3,76 ; the laser energy density for the lowest porosity (around 0.8%) of the SLMed CoCrFeNiMn highentropy alloy was~60 J/mm 3 in Fig. 2b 77 ; while the laser energy density for the lowest porosity (around 3.0%) of the SLMed Al-12Si alloy was around 30 J/mm.…”

“…2b 77 ; while the laser energy density for the lowest porosity (around 3.0%) of the SLMed Al-12Si alloy was around 30 J/mm. 3,78 However, several authors doubted the availability of the energy density as an assessment criteria of the porosity, and they pointed out that some other printing parameters, such as hatch style and laser diameter, were disregarded, which can also affect the porosity. 79 Further investigations should be conducted systematically to clarify the relationship between the porosity and processing parameters.…”

“…1,2 To date, there are many metallic materials that can be printed effectively, and the existing AM technologies are divided into two main categories: powder-fed and powder-bed systems. The powder-fed category is further classified for direct laser deposition (DLD), laser engineered net shaping methods and so on, [3][4][5][6][7][8] while the powder-bed category involves selective laser melting (SLM), selective laser sintering and electron beam melting technologies. [9][10][11][12][13][14] In general, the cooling rate for SLM is usually >10 5 K/s, which is higher than that of DLD (ranging from 10 3 to 10 5 K/s) and much higher than that for traditional casting methods that have an approximate solidification rate of 273-373 K/s.…”

Co-Cr-Mo-W powder obtained by mechanical alloying

“…Selective laser Melting (SLM) [8][9][10][11] is a sintering technique, where the components developed in the 3D software are manufactured by depositing thin layers of powders with simultaneous in situ sintering, allowing the fabrication of any format with an accurate micrometer-scale. The construction time is similar with the manufacturing route for CAD/CAM but its main advantages are: dimensional accuracy, the possibility of several geometries, no use of machining tools and especially the elimination of losses in raw materials, as the raw material is fully converted into the final product [2].…”

“…The High-Energy Ball Milling [11][12], also called mechanical alloying, is a complex process that involves the optimization of a relevant number of milling-parameters to obtain phases and/or a designed microstructure in final product. Some of the very relevant parameters, considering the final configuration of powder are: material shape, grinding configuration, grinding speed and time, kind, size and particle size distribution in grinding means, mass ratio regarding powder and balls, space available considering spheres and powder, grinding atmosphere and temperature.…”