以φ1.2 mm TC4钛合金焊丝为原材料,通过激光同轴送丝增材制造技术,结合蛇形正交路径,系统研究了增材试件在不同方向和高度下的力学性能、截面形貌、晶粒度和晶粒取向等之间的联系。研究结果表明,优化工艺参数下,试件表面成形良好(银白...以φ1.2 mm TC4钛合金焊丝为原材料,通过激光同轴送丝增材制造技术,结合蛇形正交路径,系统研究了增材试件在不同方向和高度下的力学性能、截面形貌、晶粒度和晶粒取向等之间的联系。研究结果表明,优化工艺参数下,试件表面成形良好(银白色、无飞溅),内部无气孔、裂纹等缺陷(满足NB/T 47014.2—2015 I级要求)。微观组织分析显示,增材试样底部因多次热循环形成细小网篮组织,中上部的双态组织和魏氏组织特征更为明显。晶粒取向差随高度增加而减小(底部X/Y向分别为45.9°/43.1°,顶部降至37.8°/35.9°)。力学性能测试表明,横向与纵向的抗拉强度(差异2.57%)、断后伸长率(差异4.44%)及冲击韧性(52.6 J和55.3 J)均满足CCS《材料焊接与规范2023》中对TC4板材的要求。此外,由于增材过程中热循环的影响,下层沉积组织晶粒尺寸较小,硬度较高。增材试件在横向和纵向的晶粒度、晶粒取向和组织形态相近,力学性能的各向异性较小。本研究为TC4钛合金激光同轴送丝增材制造技术的工程化应用提供了重要的实验依据。展开更多
In this paper,the microstructure of narrow gap laser welded joint of 45 mm Ti6321 titanium alloy was characterized.The microstructure characteristics of Laser self-fusion and laser-multi-pass-narrow-gapfilling layer w...In this paper,the microstructure of narrow gap laser welded joint of 45 mm Ti6321 titanium alloy was characterized.The microstructure characteristics of Laser self-fusion and laser-multi-pass-narrow-gapfilling layer were observed by metallographic microscope,and the phase morphology was analyzed by transmission electron microscope.The results show that the joint was obtained using the laser-multipass-narrow-gap welding,and no volumetric defect is observed.The weld grain of self fusion welded bead tends to be equiaxed with lots of needleα’,and the width of weld metal needleα’was 0.4μm.The heat affected zone is columnar crystal with lamellarα,and The width of heat affected zonelamellarαwas 2–4μm with a large number of dislocation tangles.The weld grains of laser-multi-pass-narrow-gap filler bead are coarse columnar grains with staggered acicularα’,and the width of acicularα’in weld metal is less than 1μm with number of dislocations.The heat affected zone is thick lamellar microstructure with a width of 2–4μm with a large number of dislocation entanglement and packing.The microstructure evolution law is related with heating temperature and cooling rate.展开更多
采用10 mm TA5钛合金,开展了万瓦级光纤激光焊接工艺研究。焊接过程高速摄影表明,当激光功率达到3~4 kW时,羽辉严重,飞溅及烟尘增加明显;不同功率焊缝截面形貌试验表明,较低焊接功率时,焊缝截面呈“楔形”,当激光功率达到6 kW以上时焊...采用10 mm TA5钛合金,开展了万瓦级光纤激光焊接工艺研究。焊接过程高速摄影表明,当激光功率达到3~4 kW时,羽辉严重,飞溅及烟尘增加明显;不同功率焊缝截面形貌试验表明,较低焊接功率时,焊缝截面呈“楔形”,当激光功率达到6 kW以上时焊缝截面过渡为“漏斗形”。采用激光功率为10~11 k W,焊接速度为1100~1500 mm/min的工艺得到成型优良的“小孔型”焊接试板,焊缝变为具有较大深宽比的典型的高能束形貌,深宽比达到2:1,对焊缝进行射线和渗透检测,满足无损检测标准要求;对焊接接头进行力学性能和工艺性能测试,结果表明:焊接接头强度可达800 MPa,弯曲测试能够满足标准,断口韧窝明显,为韧性断裂;金相测试显示,焊缝区截面为“束腰”形貌,柱状晶区明显,各柱状晶区有明显的竞争生长模式。焊缝区主要为锯齿状α+点状β。硬度检测显示,焊缝区相比母材硬度略有升高,热影响区硬度最低,满足钛合金接头硬度要求。展开更多
基金supported by the Luoyang Ship Material Institute's Scientific and Technological Innovation Project(LW190801)Zhengzhou Luoyang and Xinxiang Independent Innovation Demonstration Area(Porject No.201200211400).
文摘In this paper,the microstructure of narrow gap laser welded joint of 45 mm Ti6321 titanium alloy was characterized.The microstructure characteristics of Laser self-fusion and laser-multi-pass-narrow-gapfilling layer were observed by metallographic microscope,and the phase morphology was analyzed by transmission electron microscope.The results show that the joint was obtained using the laser-multipass-narrow-gap welding,and no volumetric defect is observed.The weld grain of self fusion welded bead tends to be equiaxed with lots of needleα’,and the width of weld metal needleα’was 0.4μm.The heat affected zone is columnar crystal with lamellarα,and The width of heat affected zonelamellarαwas 2–4μm with a large number of dislocation tangles.The weld grains of laser-multi-pass-narrow-gap filler bead are coarse columnar grains with staggered acicularα’,and the width of acicularα’in weld metal is less than 1μm with number of dislocations.The heat affected zone is thick lamellar microstructure with a width of 2–4μm with a large number of dislocation entanglement and packing.The microstructure evolution law is related with heating temperature and cooling rate.
文摘采用10 mm TA5钛合金,开展了万瓦级光纤激光焊接工艺研究。焊接过程高速摄影表明,当激光功率达到3~4 kW时,羽辉严重,飞溅及烟尘增加明显;不同功率焊缝截面形貌试验表明,较低焊接功率时,焊缝截面呈“楔形”,当激光功率达到6 kW以上时焊缝截面过渡为“漏斗形”。采用激光功率为10~11 k W,焊接速度为1100~1500 mm/min的工艺得到成型优良的“小孔型”焊接试板,焊缝变为具有较大深宽比的典型的高能束形貌,深宽比达到2:1,对焊缝进行射线和渗透检测,满足无损检测标准要求;对焊接接头进行力学性能和工艺性能测试,结果表明:焊接接头强度可达800 MPa,弯曲测试能够满足标准,断口韧窝明显,为韧性断裂;金相测试显示,焊缝区截面为“束腰”形貌,柱状晶区明显,各柱状晶区有明显的竞争生长模式。焊缝区主要为锯齿状α+点状β。硬度检测显示,焊缝区相比母材硬度略有升高,热影响区硬度最低,满足钛合金接头硬度要求。
