激光近形制造技术（1aser engineered net shaping，LENS）是一种低成本、快速制作高性能全致密金属零件的技术。采用不同的激光烧结参数研究了镍基合金的激光快速烧结成形。利用显微硬度分析和金相分析研究了扫描速度、激光功率、离焦...激光近形制造技术（1aser engineered net shaping，LENS）是一种低成本、快速制作高性能全致密金属零件的技术。采用不同的激光烧结参数研究了镍基合金的激光快速烧结成形。利用显微硬度分析和金相分析研究了扫描速度、激光功率、离焦量、送粉气流量对薄壁组织及性能的影响。微观组织观察表明，成形件组织致密，发育有枝状晶体等快速凝固组织所具有的特征。制件的平均显微硬度（HV）在1．35～1．90 GPa之间。通过实验得到了一组优化的工艺参数，并由此烧结出了结构致密、显微硬度较高的薄壁器件。展开更多
Laser shock processing（LSP）,also known as laser peening,is a novel surface treatment technique in the past few years.Compressive residual stresses which imparted by LSP are very important for improving fatigue,corro...Laser shock processing（LSP）,also known as laser peening,is a novel surface treatment technique in the past few years.Compressive residual stresses which imparted by LSP are very important for improving fatigue,corrosion and wea rresistance of metals.Finite element analysis（FEA） simulation using ABAQUS software has been applied to predict residualstresses induced by LSP on Ti-6Al-4V titanium alloy with laser pulse duration 30 ns and water confined ablation mode.The residual stress field generated by different shape laser spots was studied,and the square laser spot is shown the most suitability for avoiding stress lack phenomenon and overlapping LSP.Surface residual stresses and plastically affected depth within single square spot both increased with the increase of laser intensity and laser shock times.Furthermore,compared with circle and ellipse spot,the residual stress distribution in overlapping square spots is very uniform only with small overlapping ratio.LSP with square spot can process advantageous residual stress field,and this technique will be used widely.展开更多
文摘激光近形制造技术（1aser engineered net shaping，LENS）是一种低成本、快速制作高性能全致密金属零件的技术。采用不同的激光烧结参数研究了镍基合金的激光快速烧结成形。利用显微硬度分析和金相分析研究了扫描速度、激光功率、离焦量、送粉气流量对薄壁组织及性能的影响。微观组织观察表明，成形件组织致密，发育有枝状晶体等快速凝固组织所具有的特征。制件的平均显微硬度（HV）在1．35～1．90 GPa之间。通过实验得到了一组优化的工艺参数，并由此烧结出了结构致密、显微硬度较高的薄壁器件。
基金Project supported by the Foundation of National Key Laboratory of Science and Technology on Power Beam Processing(Grant No.9140C4505020705)
文摘Laser shock processing（LSP）,also known as laser peening,is a novel surface treatment technique in the past few years.Compressive residual stresses which imparted by LSP are very important for improving fatigue,corrosion and wea rresistance of metals.Finite element analysis（FEA） simulation using ABAQUS software has been applied to predict residualstresses induced by LSP on Ti-6Al-4V titanium alloy with laser pulse duration 30 ns and water confined ablation mode.The residual stress field generated by different shape laser spots was studied,and the square laser spot is shown the most suitability for avoiding stress lack phenomenon and overlapping LSP.Surface residual stresses and plastically affected depth within single square spot both increased with the increase of laser intensity and laser shock times.Furthermore,compared with circle and ellipse spot,the residual stress distribution in overlapping square spots is very uniform only with small overlapping ratio.LSP with square spot can process advantageous residual stress field,and this technique will be used widely.
