显微组织对Ti-15-3合金喷丸处理效果的影响

摘要

Ti-1 5-3 alloy with various microstructures was obtained by quenching,furnace cooling and quenching+aging at 500 ℃ and 540 ℃,respectively,and then shot peened with the same process.The evolution with of microstructure,residual stress,hardness and surface roughness after shot peening was investigated.The results show that a large number of deformation twins were induced in the quenched alloy,stress-induced martensitic phase transformation was found in the furnace cooled alloy,and no big change of microstructure was produced in the aged alloy after shot peening.Surface residual compressive stress of the quenched alloy was the smallest after shot peening,and that of the furnace cooled alloy was the largest.Hardness of the quenched alloy was the lowest resulted in the greatest plastic deformation range and the largest roughness after shot peening.The furnace cooled alloy showed the highest surface hardness and relatively small plastic deformation range after shot peening.The alloy aged at 500 ℃ showed the highest hardness and after shot peening the surface roughness was the smallest.With increasing aging temperature to 540 ℃,the hardness and the plastic deformation range decreased.%对Ti-15-3合金分别进行淬火、炉冷和淬火+500,540 ℃时效处理,得到不同的显微组织,然后进行相同工艺的喷丸处理,研究喷丸处理后合金显微组织、残余应力、硬度、表面粗糙度等的演化规律.结果表明:经喷丸处理后,淬火态合金组织中出现大量孪晶,炉冷态合金发生应力诱发马氏体相变,而时效态合金的显微组织无明显变化;喷丸处理后,淬火态合金的表层残余压应力最小,炉冷态的最大;淬火态合金的硬度最低,导致由喷丸处理所产生的塑性变形范围最大,表面粗糙度最大;炉冷态合金经喷丸处理后的表面硬度最大,塑性变形范围较小;500 ℃时效处理合金的硬度最高,喷丸处理后其表面粗糙度最小,时效温度升至540 ℃时,合金的硬度和塑性变形范围均减小.