Mechanical Properties of High-Strength Cu–Cr–Zr Alloy Fabricated by Selective Laser Melting

Abstract

The approximate process range for preparing the Cu–Cr–Zr alloy by selective laser melting (SLM) was determined by ANSYS simulation, and the influence of the SLM process parameters on the comprehensive properties of the SLM-formed alloy was studied by the design of experiments. The Cu–Cr–Zr alloy with optimum strength and hardness was prepared with high efficiency by optimizing the process parameters for SLM (i.e., laser power, scanning speed, and hatching distance). It is experimentally shown that tensile strength and hardness of the SLM alloy are increased by increasing laser power and decreasing scanning speed, whereas they are initially increased and then decreased by increasing the hatching distance. Moreover, strength, roughness and hardness of the SLM alloy are optimized when laser power is 460 W, scanning speed is 700 mm/s and hatching distance is 0.06 mm. The optimized properties of the SLM alloy are a tensile strength of 153.5 MPa, hardness of 119 HV, roughness of 31.384 μm and relative density of 91.62%.

CuCrZr processed by laser powder bed fusion—Processability and influence of heat treatment on electrical conductivity, microstructure and mechanical properties

“…The high number of process‐induced defects and the concomitant low density of the specimens can be considered being the main reason for the lower values found for strength and ductility for the different conditions of present work as compared to studies published in open literature. Studies from Guan et al 38 and Sun et al 41 discussed results in a similar fashion. Guan et al 38 showed a high number of pores revealed by fracture surface analysis upon tensile loading eventually being responsible for a lower strength of the alloy.…”

“…Guan et al 38 showed a high number of pores revealed by fracture surface analysis upon tensile loading eventually being responsible for a lower strength of the alloy. Sun et al 41 reported numerous LoF defects decorated by unmelted powder particles and a large number of pores leading to a significant decrease in strength and ductility. In contrast, excellent ductility and high strain to failure, respectively, rationalized based on the absence of pores and/or unmelted particles were reported by Ma et al 42 Although strength and ductility are decreased by the high amount of process‐induced defects, they do not affect the properties under quasi‐static tensile loading as severe as under cyclic loading, as has been shown for many materials processed by AM and LB‐PBF, respectively 68–71 …”

“…The volume energy density used is within the process windows of the common literature on LB-PBF of CuCrZr. 35,[38][39][40][41] The finally achieved relative density determined by optical microscopy for this parameter set is 99.4%.…”

“…Process parameters for a laser power of 400 W and a hatch distance of 110 μm, resulting in a volume energy density of 220 J/mm 3 , were developed with respect to the highest density. The volume energy density used is within the process windows of the common literature on LB‐PBF of CuCrZr 35,38–41 . The finally achieved relative density determined by optical microscopy for this parameter set is 99.4%.…”

“…Further investigations on LB‐PBF CuCrZr were conducted by Sun et al 41 and Ma et al 42 The former group showed that, using a constant power, the influence of scan speed on the density of the fabricated parts was higher than that of the hatching distance. Furthermore, tensile strength of the material was improved by increasing laser power and decreasing scan speed, whereas tensile strength initially increased and then decreased with increasing hatching distance.…”