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Chinese Welding Society

Harbin Welding Institute

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Microstructure and properties of the joints of ZrO2 ceramic/ stainless steel brazed in vacuum with AgCuTi active filler metal
Liu Xu, Huang Xiaomeng, Ma Huibin, Shi Xiumei, Qi Yuefeng
2018, 27(2): -. doi: 10.12073/j.cw.20180116001
[Abstract](92) [PDF 778KB](12)
Abstract:
The ZrO2 ceramic was successfully jointed to stainless steel by vacuum brazing with active filler metal. The AgCuTi active filler metal was used and the joining was performed at a temperature of 850 ℃ for 10 min. The microstructures of the joints were characterized by metallographic microscopy, scanning electron microscopy(SEM), and energy dispersive spectroscopy(EDS).Metallographic microscopy analysis shows that the morphology of the cross section was a sandwich structure and the TiO is observed in the surface of ZrO2/ stainless steel. The diffusion and enrichment of the elements are the key roles in the brazing of ZrO2 ceramic and stainless steel. The formation of TiCu compounds inhibited the further diffusion of titanium into stainless steel or the ZrO2 ceramic to form TiO compound. In the experimental conditions, the average tensile strength is 80MPa for the joint of ZrO2 ceramic / AgCuTi/stainless steel systems. A complete joint is formed between the ZrO2 ceramic and stainless steel with the leakage rate at the degree of 10-12 Pa·m3/s.
Effects of fragments on W-DLC films properties under boundary lubrication condition in the friction system
Zhan Hua, Wang Ruijun, Li Zhendong, Xu Tianyang, Wang Weiping
2018, 27(2): -. doi: 10.12073/j.cw.20171204001
[Abstract](61) [PDF 1308KB](2)
Abstract:
Effects of film fragments in the friction system on friction and wear properties of tungsten doped diamond-like carbon films (W-DLC) were studied in the condition of boundary lubrication. It could be observed that the average friction coefficient was increased after introducing film fragments into the friction system, where these film fragments can accelerate the breaking of the extreme thin oil film which could separate two friction surfaces when the system is under boundary lubrication conditions. The increasing friction load can accelerate the friction chemical reaction on the friction interface and lead to the crushing effect on film fragments, which decreased the friction coefficient of friction system. It was also found that the wear width, depth, and volume of the film increased by introducing film fragments and applying great load.
Study of joining mechanism of ABS polymer and steel/aluminum by resistance spot welding
Zhang Changqing, Lü Guangming, Jin Xin, Wang Weijie, Jin Shaolong
2018, 27(2): -. doi: 10.12073/j.cw.20171218001
[Abstract](68) [PDF 924KB](2)
Abstract:
The joining of metal and polymer is an increasingly important method to get lightweight components in the development of manufacturing industry nowadays. In this article, metal and polymer lap joint was achieved by means of resistance spot welding (RSW) and ultrasonic assistance welding (UAW). The joining mechanism of lap joint was analyzed by OM, TEM on microstructure at the interface of lap joints and XPS and IR spectra was discussed based on the following different ones: mechanical-interlocking, diffusion bond and coordination bond. The results showed that it was the combined action that played an important role in the effective joining work. Besides, ultrasonic assistance was used in the study to aid welding process based on its high-frequency ultrasonic vibration, which made joints shaping better and improved tensile strength visibly contrast to joints with the same lower heat input parameters.
Numerical simulation of horizontal transversal displacement under different fixed clamping force of welding fixture for superalloy during TIG welding
Zhang Wenyang, Guo Shaoqing, Yuan Zhongjin, Tang Siyi, Liang Jiayu, Zhang Xuejun
2018, 27(2): -. doi: 10.12073.j.cw.20180119001
[Abstract](67) [PDF 1329KB](1)
Abstract:
A numerical model is established by Abaqus software for superalloy during tungsten inert gas(TIG) welding with welding fixture to simulate the weld temperature filed, stress and strain field, and weld plate's horizontal trasnsveral shift. The clamp force perpendicular to the weld plate varying with welding time was analyzed. The maximum clamp force during welding process was calculated. Under the condition of insufficient of clamping force, a half or one third of the maximum clamp force for example, the weld plate's horizontal transversal displacement could happen and also be computed.
Influence of welding parameters on temperature field characteristics during laser welding of TA15 by infrared thermography
Duan Aiqin, Gong Shuili, Huang Song
2018, 27(2): -. doi: 10.12073/j.cw.20171116001
[Abstract](55) [PDF 3729KB](3)
Abstract:
Using an infrared thermographic technique, the temperature field during laser welding of TA15 is quantitatively measured and investigated. The influence of two welding parameters on the weld temperature distribution is analyzed and the mechanism is discussed. New conclusions are drawn that are different from conventional weld temperature distributions. For the face of the weld, changes in welding speed induce changes in the temperature distribution because of different heat inputs and the cooling effect. Similar temperature features in the welds are observed for all speeds, which exhibit a relatively low temperature area below 1 500 ℃ between the high temperature area in the position of laser incidence and the sub-high temperature area at the end of the molten pool. For the influence of laser power on the face of the weld, the temperature on the weld is higher for P = 2.8 kW compared to P = 2.0 kW, especially the temperature in the sub-high temperature area. However, for the temperature field of the back of the weld, the influence of welding speeds is quite different compared to the results for the face of the weld. The highest temperature does not locate in the keyhole area, but instead in the middle of the molten pool. And there are different temperature features at different speeds. When v = 6 m/min, the temperature field is like a uniform color belt and the temperature along the center of the weld fluctuates between 300 and 450 ℃. When v = 4 m/min, the transient temperature distribution is not uniform and is unstable at different times. However, for v = 2.4 m/min and lower speeds, the temperature field becomes stable. The influence of laser power on the back of the weld temperature field is more complex. The measured temperature does not increase with increasing laser power, which seems to conflict with the conventional thermal conduction theory. This may be related with the characteristics of the keyhole area.
Microstructure evolution and mechanical properties of the Sip/Zn-Al composite joints by ultrasonic-assisted soldering in air
Kang Yuqing, Shen Haoran, Fu Yang, Chen Yunru, Xu Chang, Li Xin, Gu Keyun, Li Xiaohai, An Ledong, Wang Qian
2018, 27(2): -. doi: 10.12073/j.cw.20171227001
[Abstract](47) [PDF 1111KB](1)
Abstract:
Hypereutectic Al-27Si alloys were joined without flux by ultrasonic-assisted soldering at 420 ℃ in air using Zn-5Al the filler alloys, and Si particulate-reinforced Zn-Al based composites filler joints were obtained. The ultrasonic vibration introduced into soldering could influence the migration of Si particles and the microstructure of solidified Zn-Al based alloys. Both the distribution of Si particles and microstructure of the solidified Zn-Al based alloys affected the shear strength of joints. The shear strength increased with the ultrasonic vibration time. The highest average shear strength of joints reached to ~68.5 MPa. Transcrystalline rupture mode was observed on the fracture surface.
Numerical simulation of DE-GMAW of magnesium alloy cylinder
Fang Naiwen, Wang Liping, Li Liansheng, Zhang Haibo, Zhang Yingchun, Ma QingJun, Song Nan
2018, 27(2): -. doi: 10.12073/j.cw.20180110001
[Abstract](50) [PDF 3493KB](3)
Abstract:
Double-electrode gas shielded arc welding (DE-GMAW) was used to weld the magnesium alloy cylinder with the diameter of 200 mm and the thickness of 6 mm. In order to study the residual stress distribution of AZ31B magnesium alloy welding point, numerical simulation of welding temperature field, stress field and residual stress were carried out by MSC.marc software. The results show that the residual stress in the weld and the heat affected zone is large, and with the increase of the distance away from the weld center, the residual stress decreases. In most areas, the longitudinal residual stress is greater than the transverse residual stress (except for the inside and outside surfaces of the weld), all of which provides theoretical support for the study of magnesium alloy welding residual stress.
Research progress of laser cladding self-fluxing alloy coatings on titanium alloys
Liu Jiaqi, Yu Huijun, Chen Chuanzhong
2018, 27(2): -. doi: 10.12073/j.cw.20180308001
[Abstract](46) [PDF 1054KB](1)
Abstract:
Laser cladding is a new surface modification technology, and is widely used for fabricating wear and corrosion resistant composites coatings. Self-fluxing alloys have many advantages, such as excellent properties of deoxidizing and slagging, high wear resistance, low melting point and easy cladding, and are often used in laser cladding to improve wear and corrosion resistance of titanium and its alloys. In this paper, the recent development of Ni-based and Co-based self-fluxing alloy coatings which includes the influence of rare earth and ceramic particles in coatings are summarized. Besides, the effects of processing parameters, such as laser power and scanning speed, on coatings are reviewed. Finally, the trend of development in the future is forecasted.
Numerical analysis of flow-thermal coupling in micro-plasma welding pool of thin-wall part
Liu Haihua, Chen Haojie, Liu Wenji, Wang Tianqi, Yue Jianfeng
2018, 27(2): -. doi: 10.12073.j.cw.20171116002
[Abstract](44) [PDF 1148KB](3)
Abstract:
The formed characteristics of thin-wall part is studied when it is in the process of MPAW. Finite element method is used to simulate the temperature field coupling flow field in the welding of thin-wall part. It is found that because of the obvious effect of heat accumulation in cross-section, where the distribution of temperature field area presents trapezoidal inverted approximately in the molten pool and the non-molten pool area presents level. The surface tension, the electromagnetic force and buoyancy are considered for analyzing the effects on the fluid flow of welding-pool. It can be obtained that the surface tension is the main driving force in the welding pool, which is far greater than electromagnetic force and buoyancy.
Optimization of back bead geometry in the PMAG-TIG twin arc hybrid root welding process using grey based Taguchi method
Liu Liming, Zhou Yanbin, Shi Jipeng
2018, 27(1): 1-9.   doi: 10.12073/j.cw.20170808001
[Abstract](52) [PDF 1038KB](1) [Cited Count](0)
Influence of flux composition on microstructure and oxygen content of low carbon steel weldments in submerged arc welding
Brijpal Singh
2018, 27(1): 10-19.   doi: 10.12073/j.cw.20171201001
[Abstract](46) [PDF 969KB](1) [Cited Count](0)
A new weld repair technique for friction stir welded aluminium structure: inertia friction pull plug welding
Wang Guoqing, Zhao Yanhua, Zhang Lina, BaiJingbin, Zhu Ruican
2017, 26(4): 56-64.   doi: 10.12073/j.cw.20170422001
[Abstract](116) [PDF 0KB](1) [Cited Count](0)
Microstructure and properties of the joints of ZrO2 ceramic/ stainless steel brazed in vacuum with AgCuTi active filler metal
Liu Xu, Huang Xiaomeng, Ma Huibin, Shi Xiumei, Qi Yuefeng
2018, 27(2): -.   doi: 10.12073/j.cw.20180116001
[Abstract](92) [PDF 778KB](12) [Cited Count](0)
Microstructure and microhardness of Co-8.8Al-9.8W superalloy cladding layer with different boron content
Xu Yangtao, Lou Dechao, Xia Rongli, Xia Tiandong
2017, 26(4): 48-55.   doi: 10.12073/j.cw.20170320001
[Abstract](243) [PDF 0KB](1) [Cited Count](0)
Effects of fragments on W-DLC films properties under boundary lubrication condition in the friction system
Zhan Hua, Wang Ruijun, Li Zhendong, Xu Tianyang, Wang Weiping
2018, 27(2): -.   doi: 10.12073/j.cw.20171204001
[Abstract](61) [PDF 1308KB](2) [Cited Count](0)
Laser-pulsed MIG hybrid welding technology of A6N01S aluminum alloy
Lei Zhen, Li Xiaoyu, Xu Fujia, Wang Ren, Chang Yunfeng
2017, 26(4): 10-19.   doi: 10.12073/j.cw.20170815001
[Abstract](248) [PDF 0KB](0) [Cited Count](0)
Study of joining mechanism of ABS polymer and steel/aluminum by resistance spot welding
Zhang Changqing, Lü Guangming, Jin Xin, Wang Weijie, Jin Shaolong
2018, 27(2): -.   doi: 10.12073/j.cw.20171218001
[Abstract](68) [PDF 924KB](2) [Cited Count](0)
The influence of gradient mismatches on mechanical properties and microstructure of 2219-T6 aluminum alloy VP-TIG joints
Lü Zongliang, Li Chong, Wan Long, Hou Zhenguo, Chen Xiaoxia, Wu Hao, Huang yongxian
2017, 26(4): 20-28.   doi: 10.12073/j.cw.20170901001
[Abstract](79) [PDF 0KB](0) [Cited Count](0)
Mechanical properties and microstructure of pure nickel PAW and PAW-TIG welded joints
Wang Xijing, Wang Boshi, Zhang Liangliang, Liu Xiao, Yang Chao
2017, 26(4): 37-47.   doi: 10.12073/j.cw.20170629001
[Abstract](242) [PDF 0KB](3) [Cited Count](0)