(1. 江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013；
2. 寶雞市博信金屬材料有限公司，寶雞 721013)
摘 要: 采用最大輸出激光脈沖能量為12.5 J的Thales Laser激光器，對(duì)TA1純鈦薄板進(jìn)行激光沖擊成形，并運(yùn)用激光共聚焦掃描顯微鏡、透射電鏡和有限元模擬等方法對(duì)沖擊表層的殘余應(yīng)力和微觀結(jié)構(gòu)進(jìn)行分析。結(jié)果表明：功率密度為6.11 GW/cm2時(shí)，單次沖擊成形效果更好；多次沖擊工藝更適合于較小的功率密度3.06 GW/cm2。沖擊斷口由大量的韌窩、少量的撕裂棱和層裂組成，斷口呈韌性斷裂，破裂表現(xiàn)為減薄機(jī)制和層裂機(jī)制。沖擊層存在大量的孿晶、位錯(cuò)墻、周期性波紋等結(jié)構(gòu)。激光沖擊使鈦薄板表面引入高幅值的殘余壓應(yīng)力，呈“W”形分布，多次沖擊中心區(qū)易形成殘余拉應(yīng)力。
關(guān)鍵字: TA1鈦薄板；激光沖擊成形；殘余壓應(yīng)力；微觀結(jié)構(gòu); 破裂機(jī)制；數(shù)值模擬
（1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
2. Baoji Boxin Metal Materials Ltd, Baoji 721013, China）
Abstract:The TA1 pure titanium sheet was laser shocked by the Thales Laser with the maximum output laser pulse energy for the 12.5 J, and the residual stress and microstructure on the shocked layer were analyzed by confocal laser scanning microscope (CLSM), transmission electron microscope (TEM) and finite element simulation. The results show that the laser with power density of 6.11 GW/cm2 is used to single impact titanium sheet with better formation; multiple impact process is more suitable for small power density of 3.06 GW/cm2. The fracture is composed of a large number of dimples, a small amount of tearing ridges and spallation, which is ductile fracture. The fracture mechanism is the thinning and spallation. A large amount of deformed twins, dislocation tangles and periodic corrugated structure are gained. High amplitude residual compressive stress is gained on the surface of titanium sheet, which is in distribution shape of “W”, the residual tensile stress generates in the central zone after multiple impacts gradually.
Key words: TA1 titanium sheet; LSF; compressive residual stress; microstructure; rupture mechanism; numerical simulation
