In order to overcome the problems of many pores,large deformation and unstable weld quality of traditional laser welded aluminumcopper alloy joints,a red-blue dual-beam laser source and a swinging laser were introduce...In order to overcome the problems of many pores,large deformation and unstable weld quality of traditional laser welded aluminumcopper alloy joints,a red-blue dual-beam laser source and a swinging laser were introduced for welding.T2 copper and 6063 aluminum thin plates were lap welded by coaxial dual-beam laser welding.The morphology of weld cross section was compared to explore the influence of process parameters on the formation of lap joints.The microstructure characteristics of the weld zone were observed and compared by optical microscope.The results show that the addition of laser beam swing can eliminate the internal pores of the weld.With the increase of the swing width,the weld depth decreases,and the weld width increases first and then decreases.The influence of welding speed on the weld cross section morphology is similar to that of swing width.With the increase of welding speed,the weld width increases first and then decreases,while the weld depth decreases all the time.This is because that the red laser is used as the main heat source to melt the base metals,with the increase of red laser power,the weld depth increases.As an auxiliary laser source,blue laser reduces the total energy consumption,consequently,the effective heat input increases and the spatter is restrained effectively.As a result,the increase of red laser power has an enhancement effect on the weld width and weld depth.When the swing width is 1.2 mm,the red laser power is 550 W,the blue laser power is 500 W,and the welding speed is 35 mm/s,the weld forming is the best.The lap joint of T2 copper and 6063 aluminum alloy thin plate can be connected stably with the hybrid of blue laser.The effect rules of laser beam swing on the weld formation were obtained,which improved the quality of the joints.展开更多
Through laser swing welding of dissimilar steels,the microstructure and properties of welded joints of dissimilar steels under different heat treatment processes were investigated.In the test,the equilibrium phase dia...Through laser swing welding of dissimilar steels,the microstructure and properties of welded joints of dissimilar steels under different heat treatment processes were investigated.In the test,the equilibrium phase diagrams of the base materials 3Cr13 and VG10 were calculated by JMATPro software.The microstructures of the different regions of the welded joints after the original and heat treatment were analyzed by XRD and SEM,and the changes of the microhardness were tested.The test results show that a martensite-like structure is generated at the base material on the 3Cr13 side of the original welded joint,and a non-convective mixing zone exists in the fusion zone on the VG10 side.At this location,a block-like,island-like structure is embedded in the base material.There were lamellar carbide formation on this structure.After heat treatment,the amount of carbides in the welded joints is reduced,but the primary carbides in the VG10 base metal are difficult to eliminate by heat treatment.In addition,the lamellar carbides in the VG10 side fusion zone are polymerized to form network carbides.The hardness of the base metal near the fusion line on both sides of the original welded joint is relatively large,and the hardness of the heat affected zone gradually decreases with increasing distance from the center of the weld.After heat treatment,the overall hardness of the welded joint has increased significantly.Among them,the hardness increase is greatest at the quenching temperature of 1050°C,and VG10 can reach about 830 HV.展开更多
The growing interest in additive manufacturing of GH4169 alloy was accompanied by the demand on spherical GH4169 powders with high performance.The powder particles were treated by radio frequency plasma with the diffe...The growing interest in additive manufacturing of GH4169 alloy was accompanied by the demand on spherical GH4169 powders with high performance.The powder particles were treated by radio frequency plasma with the different feeding rates.The microstructure and morphology,the particle size distribution of as-treated powders were studied by scanning electron microscopy and laser particle size analysis.It was demonstrated that GH4169 powders with extremely fine followability were obtained by radio frequency plasma spheroidization technology.With the same plasma parameters,the spheroidization efficiency of the particles varied with the feeding rates.When the rate of the powder feeding rates was too small,the excessive absorption of the heating by the powders caused vaporization,then the collection decreased.When the feeding rates was too large,the powder particles were insufficiently absorbed,resulting in defects in the powders.The microstructure of the as-treated spherical particles was mainly cell crystals,columnar crystals,and even microcrystals.Under the suitable plasma parameters,the resulting powders haved a slightly increased average particle size,excellent spheroidization,surface smoothness,followability,and bulk ratio.展开更多
针对16mm厚TA2钛合金板材进行等离子打底+钨极氩弧焊盖面的复合焊(plasma-tungsten inert gas welding,P-T复合焊),采用小孔型等离子焊实现不开坡口单面焊双面成形。结果表明,焊缝的组织为少量锯齿形α-Ti+针状马氏体,未发现成分偏析与...针对16mm厚TA2钛合金板材进行等离子打底+钨极氩弧焊盖面的复合焊(plasma-tungsten inert gas welding,P-T复合焊),采用小孔型等离子焊实现不开坡口单面焊双面成形。结果表明,焊缝的组织为少量锯齿形α-Ti+针状马氏体,未发现成分偏析与聚集、夹杂物及裂纹等缺陷。热影响区及熔合线为锯齿形α-Ti+板条马氏体组织。焊缝的抗拉强度达到486 MPa,与母材相当,且断裂位置位于热影响区。在较优的工艺参数下进行焊接,焊缝及热影响区的维氏硬度分别为175 HV和170 HV,均高于母材。因此P-T组合焊接能实现钛合金厚板焊接,在厚板钛合金焊接中具有广泛的应用前景。展开更多
基金supported by Guangdong Science and Technology Plan Project(Grant No.20170902,No.20180902)Yangjiang Science and Technology Plan Project(Grant No.SDZX2020063)+1 种基金Shenzhen Key Projects of Innovation and Entrepreneurship Plan Technology(JSGG20210420091802007)Yunfu 2023 Science and Technology Plan Project(S2023020201).
文摘In order to overcome the problems of many pores,large deformation and unstable weld quality of traditional laser welded aluminumcopper alloy joints,a red-blue dual-beam laser source and a swinging laser were introduced for welding.T2 copper and 6063 aluminum thin plates were lap welded by coaxial dual-beam laser welding.The morphology of weld cross section was compared to explore the influence of process parameters on the formation of lap joints.The microstructure characteristics of the weld zone were observed and compared by optical microscope.The results show that the addition of laser beam swing can eliminate the internal pores of the weld.With the increase of the swing width,the weld depth decreases,and the weld width increases first and then decreases.The influence of welding speed on the weld cross section morphology is similar to that of swing width.With the increase of welding speed,the weld width increases first and then decreases,while the weld depth decreases all the time.This is because that the red laser is used as the main heat source to melt the base metals,with the increase of red laser power,the weld depth increases.As an auxiliary laser source,blue laser reduces the total energy consumption,consequently,the effective heat input increases and the spatter is restrained effectively.As a result,the increase of red laser power has an enhancement effect on the weld width and weld depth.When the swing width is 1.2 mm,the red laser power is 550 W,the blue laser power is 500 W,and the welding speed is 35 mm/s,the weld forming is the best.The lap joint of T2 copper and 6063 aluminum alloy thin plate can be connected stably with the hybrid of blue laser.The effect rules of laser beam swing on the weld formation were obtained,which improved the quality of the joints.
基金Development of High-end Manufacturing Equipment and Materials for the Metal Knife and Scissors Industry in Yangjiang(510224133196)Yangjiang High Power Laser Application Laboratory Co.,Ltd.Supports the Construction of New Research and Development Institutions in the East and West of Guangdong(809099997119)Development of Additive Manufacturing Technology for Blade Laser Cladding(2017036)。
文摘Through laser swing welding of dissimilar steels,the microstructure and properties of welded joints of dissimilar steels under different heat treatment processes were investigated.In the test,the equilibrium phase diagrams of the base materials 3Cr13 and VG10 were calculated by JMATPro software.The microstructures of the different regions of the welded joints after the original and heat treatment were analyzed by XRD and SEM,and the changes of the microhardness were tested.The test results show that a martensite-like structure is generated at the base material on the 3Cr13 side of the original welded joint,and a non-convective mixing zone exists in the fusion zone on the VG10 side.At this location,a block-like,island-like structure is embedded in the base material.There were lamellar carbide formation on this structure.After heat treatment,the amount of carbides in the welded joints is reduced,but the primary carbides in the VG10 base metal are difficult to eliminate by heat treatment.In addition,the lamellar carbides in the VG10 side fusion zone are polymerized to form network carbides.The hardness of the base metal near the fusion line on both sides of the original welded joint is relatively large,and the hardness of the heat affected zone gradually decreases with increasing distance from the center of the weld.After heat treatment,the overall hardness of the welded joint has increased significantly.Among them,the hardness increase is greatest at the quenching temperature of 1050°C,and VG10 can reach about 830 HV.
基金supported financially by Yangjiang City Hardware Knives and Scissors and Nickel Alloy Industry Additive Manufacturing Technology Innovation Platform Construction(No.2015B020221002)Guangdong Province‘Sailing Plan’Introduces Special Funding for Innovation and Entrepreneurship Team(No.2015YT02G090)+1 种基金High-end Knives and Scissors Additive Manufacturing(3D Printing)of Engineering Technology Research Center in Guangdong Province(Grant No.509153168061)Initial Construction Subsidy for New Research and Development Institutions of Yangjiang City Hardware Knives and Scissors Industry and Technology Research(Grant No.611229498090)。
文摘The growing interest in additive manufacturing of GH4169 alloy was accompanied by the demand on spherical GH4169 powders with high performance.The powder particles were treated by radio frequency plasma with the different feeding rates.The microstructure and morphology,the particle size distribution of as-treated powders were studied by scanning electron microscopy and laser particle size analysis.It was demonstrated that GH4169 powders with extremely fine followability were obtained by radio frequency plasma spheroidization technology.With the same plasma parameters,the spheroidization efficiency of the particles varied with the feeding rates.When the rate of the powder feeding rates was too small,the excessive absorption of the heating by the powders caused vaporization,then the collection decreased.When the feeding rates was too large,the powder particles were insufficiently absorbed,resulting in defects in the powders.The microstructure of the as-treated spherical particles was mainly cell crystals,columnar crystals,and even microcrystals.Under the suitable plasma parameters,the resulting powders haved a slightly increased average particle size,excellent spheroidization,surface smoothness,followability,and bulk ratio.
基金National Natural Science Foundation of China(52161007)Key Technical Project of Shenzhen Innovation and Entrepreneurship Plan(JSGG20210420091802007)+1 种基金Guangdong Province Science and Technology Special Fund Project(SDZX2020009)Sichuan Provincial Key Lab of Process Equipment and Control Open Fund Project(GK202104,GK202106)。
