High-throughput Screening Of Optimum Process Parameters For Additive Manufacturing Amorphous Alloys

Amorphous alloy is also called"metal glass".It is formed by the liquid superheated melt during the rapid cooling process,and its unnecessary liquid structural features are retained,thus possessing many characteristics of both metal and glass.Compared with traditional crystalline alloys,amorphous alloys have outstanding mechanical properties,such as higher elastic limit to Young's modulus ratio and higher fracture toughness.Due to these excellent properties,amorphous alloys can be applied in many engineering fields.However,due to the limitations of the traditional preparation method,the size of the prepared amorphous alloy is small and poor shaping of amorphous alloys makes it difficult to carry out subsequent processing,which greatly limits the industrial application of the amorphous alloy.However,flaws,such as cracks,gas porosity,and crystalline phases,are always formed accompanied by the process of LAM,which seriously worsens the mechanical and physical properties of the resulting amorphous alloy.Based on the above problems,here,we take Zr₅₁Ti₅Cu₂₅Ni₁₀Al₉ amorphous alloy as the research object,ultrasonic wave detection technology was used to high-throughput screen the optimum process parameters.The parameter library,which constituted by a series of rectangular Zr₅₁ BMG samples is rapidly fabricated by the laser additive manufacturing method under continuously changed combinations of laser power and travel speed.The ultrasonic attenuation factor,which is sensitive to the flaws,is used as the monitor to screen the parameters of the BMGs.Using this approach,the laser power of 1300 W and travel speed of 600 mm/min are estimated as the optimum parameter combination for the BMGs with the slightest flaws.The bulk Zr-based amorphous alloy specimen with the optimal process parameters was prepared.The amorphous-phase dominated microstructure and the sufficiently high tensile strength of the subsequent fabricated large-sized Zr51 BMG sample confirmed the feasibility of high-throughput ultrasonic wave testing.In the meantime,a comprehensive investigation of hidden pore defects in a typical model BMG is performed by using the computed tomography technology.The overall porosity of the BMG samples is increased with increasing laser power.However,the variation trends of the proportions for different-size pores are not the same.This opposite evolution trends of pores with the increasing laser power is analyzed from the Marangoni effect in the molten pool flow.