摘要
在400 W激光功率和不同扫描速度(2和8mm/s)下对典型商用铝合金(1050)板材进行激光重熔试验,并采用多种表征技术对激光重熔前后样品的显微组织及织构特征进行精细表征。结果表明,原材料铝合金具有典型的再结晶组织,由尺寸较均匀的近等轴晶(平均晶粒尺寸为(20.4±15.4)μm)和一些亚微米尺度的第二相颗粒共同组成。经2和8 mm/s的激光重熔加工后,样品表层均出现以柱状晶为主要组织特征(晶内存在亚微米级析出相)的重熔层,且明显较基体组织粗大。对比发现,当扫描速度从2升至8mm/s时,重熔层深度明显降低,其内部柱状晶的平均宽度也由(38.0±4.3)μm降至(33.9±2.0)μm。同时,晶内析出相也得到显著细化,而其数密度则大幅增加。激光表面重熔未改变1050铝合金的主要织构特征,即仍以{100}<001>立方织构为主,但织构强度明显增加。
A typical commercial Al alloy(1050)sheet was subjected to laser surface remelting(LSR)treatment at 400 W and different scanning speeds(2 and 8 mm/s),with dedicated microstructural and textural characterization made for original and LSRed specimens by using multiple characterization techniques.Results show that the as-received material has a typically recrystallized structure consisting of near-equiaxed grains(average grain size(20.4±15.4)μm)and many submicron second phase particles(SPPs).After the LSR treatment,remelting layers of the 2 mm/s and 8 mm/s specimens are mainly composed of columnar grains(with dense fine SPPs inside them),which are coarser than the near-equiaxed grains in the substrate.As the laser scanning speed increases from 2 to 8 mm/s,the depth of the remelted layer is evidently reduced,with the average width of the columnar grains decreasing from(38.0±4.3)to(33.9±2.0)μm.Meanwhile,the SPPs inside grains are significantly refined with largely increased number density.The LSR does not change the main textural characteristic({100}á001ñcube component)of the as-received sheet but leads to the significantly increased textural intensity.
作者
张成全
柴林江
李琪琪
麻彦龙
王辉
安旭光
Cheng-quan ZHANG;Lin-jiang CHAI;Qi-qi LI;Yan-long MA;Hui WANG;Xu-guang AN(College of Materials Science and Engineering,Chongqing University of Technology,Chongqing 400054,China;Interdisciplinary Materials Research Center,Institute for Advanced Study,Chengdu University,Chengdu 610106,China)
基金
the financial supports from the University Innovation Research Group of Chongqing,China(No.CXQT20023)
the Graduate Student Innovation Program of Chongqing University of Technology,China(No.CLGYCX20203006)。
关键词
铝合金
激光表面重熔
显微组织
织构
扫描速度
硬度
aluminum alloy
laser surface remelting
microstructure
texture
scanning speed
hardness
