Investigation of homogenization in surface microstructure and corrosion behavior of Ti6Al4V alloy prepared by SLM
Ti6Al4V alloy with the densification of 97.5％was prepared by selective laser melting(SLM)process.The homogenization of the microstructures of XOY plane in the vertical construction direction and the XOZ plane in the parallel construction direction was carried out by high-energy shot peening and ensuing annealing.Finally,the electrochemical performances of the as-printed sample,the shot peening sample and the annealing sample after shot peening were measured.The results show that the microstructures of the XOY and XOZ plane in the as-printed sample are obviously refined and tend to be uniform after the shot peening.Shot peening does not change the position of the diffraction peak or produce a new diffraction peak,but can widen the diffraction peak.When the samples are annealed at different temperatures after shot peening,the grains in XOY and XOZ plane gradually grow with the increase of annealing temperature.The typical duplex microstructure including α and β phase for Ti6Al4V alloy can be obtained after annealing at 780℃for both planes.The significant difference in the electrochemical corrosion behavior can be observed between the XOY plane and the XOZ plane in the as-printed sample,and the XOY plane has a smaller corrosion tendency and higher corrosion resistance than XOZ plane.This difference can be significantly reduced by the comprehensive treatment in annealing after shot peening,and the corrosion resistance is further improved.Annealing at 780℃after shot peening in general is the best process.
万方数据
维普
