Virtual Development of Process Parameters for Bulk Metallic Glass Formation in Laser-Based Powder Bed Fusion

The development of process parameters and scanning strategies for bulk metallic glass formation during additive manufacturing is time-consuming and costly. It typically involves trials with varying settings and destructive testing to evaluate the final phase structure of the experimental samples. In this study, we present an alternative method by modelling to predict the influence of the process parameters on the crystalline phase evolution during laser-based powder bed fusion (PBF-LB). The methodology is demonstrated by performing simulations, varying the following parameters: laser power, hatch spacing and hatch length. The results are compared in terms of crystalline volume fraction, crystal number density and mean crystal radius after scanning five consecutive layers. The result from the simulation shows an identical trend for the predicted crystalline phase fraction compared to the experimental estimates. It is shown that a low laser power, large hatch spacing and long hatch lengths are beneficial for glass formation during PBF-LB. The absolute values show an offset though, over-predicted by the numerical model. The method can indicate favourable parameter settings and be a complementary tool in the development of scanning strategies and processing parameters for additive manufacturing of bulk metallic glass.

RESEARCH INTO GLASS FORMATION IN AS2S3-ER2S3 SYSTEM

Glass formation in the As2S3-Er2S3 system was investigated by the methods of physicochemical differential thermal (DTA), X-ray phase (RFA), microstructural (MCA) analyzes, as well as by measuring microhardness, glass regions were determined and some physicochemical properties were studied. It was found that in the As2S3Er2S3 system based on As2S3 upon slow cooling, the glass-forming regions extend to 20 mol. % Er2S3. In the concentration range 20-30 mol. % Er2S3 alloys are glass-crystalline. In the system at room temperature on the basis of As2S3, solid solutions reach 2 mol% Er2S3, and on the basis of Er2S3, solid solutions have practically not been established.

RESEARCH IN THE FIELD OF GLASS FORMATION IN THE ASS-ERS SYSTEM

In order to determine the region of glass formation between the AsS and ErS compounds, we studied the methods of physicochemical analysis: differential thermal (DTA), X-ray phase (XRD), microstructural (MCA), as well as by measuring microhardness and density. The eutectic composition between the AsS and ErS compounds is 10 mol. % ErS and temperature 280oC. At a cooling rate v = 102 K / min, the glass transition region based on AsS reaches 10 mol. % ErS. Some physicochemical properties of alloys from the region of glass formation have been investigated. The area of homogeneity based on AsS reaches up to 1.5 mol. % ErS.