A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El...A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El)on the defects,melt pool morphology,microstructure,and properties of the alloy was systematically investigated.The results show that the optimized process parameters for preparing Cu−Cr−Nb−Y alloy with relative density over 99.5%are P=300−350 W and v=650−800 mm/s,corresponding to El=0.375−0.538 J/mm.When E_(l)<0.3 J/mm,increasing P or decreasing v can enhance the continuity and size of the melt pool,reduce the lack-of-fusion defects,and increase the relative density.However,excessively high E_(l)leads to a deeper melt pool,more keyholes,and reduced relative density.The grain size of the as-built Cu−Cr−Nb−Y alloy shows a bimodal distribution,with fine grains at the center and coarse grains at the edge of the melt pool.Increasing P or decreasing v increases the average grain size and(110)texture intensity.The alloy fabricated with P=350 W and v=800 mm/s displays the highest relative density of 99.82%.The yield strength,tensile strength,and elongation are(443±5)MPa,(699±4)MPa,and(17.1±0.7)%,respectively.展开更多
基金financially supported by the Project of Chinese Academy of Engineering(Nos.2019-XZ-11 and 2023-XY-18)the Open Fund of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials of China(No.HKDNM201907)。
文摘A novel Cu−4.8Cr−2.2Nb−0.15Y(at.%)alloy was fabricated by employing the laser powder bed fusion with different processing parameters.The influence of laser power(P),scanning speed(v),and laser linear energy density(El)on the defects,melt pool morphology,microstructure,and properties of the alloy was systematically investigated.The results show that the optimized process parameters for preparing Cu−Cr−Nb−Y alloy with relative density over 99.5%are P=300−350 W and v=650−800 mm/s,corresponding to El=0.375−0.538 J/mm.When E_(l)<0.3 J/mm,increasing P or decreasing v can enhance the continuity and size of the melt pool,reduce the lack-of-fusion defects,and increase the relative density.However,excessively high E_(l)leads to a deeper melt pool,more keyholes,and reduced relative density.The grain size of the as-built Cu−Cr−Nb−Y alloy shows a bimodal distribution,with fine grains at the center and coarse grains at the edge of the melt pool.Increasing P or decreasing v increases the average grain size and(110)texture intensity.The alloy fabricated with P=350 W and v=800 mm/s displays the highest relative density of 99.82%.The yield strength,tensile strength,and elongation are(443±5)MPa,(699±4)MPa,and(17.1±0.7)%,respectively.
