Reliable Copper Spot Welding with IR Laser Radiation through Short Prepulsing

Moalem, Anas; Witzendorff, Philipp von; Stute, U.; Overmeyer, Ludger

doi:10.1016/j.procir.2012.07.079

Cited by 13 publications

(6 citation statements)

References 5 publications

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“…High peak intensities were addressed by the use of pulsed laser systems [5,6]. Another method to achieve high peak intensities is the use of single mode fiber lasers with maximum intensities of up to 10 12 W/cm² [12,13].…”

Section: Variable Methodsmentioning

confidence: 99%

“…Due to these material properties only a small proportion of the total emitted laser power is available for the process. Therefore, pulsed lasers with high peak intensities are currently often used for welding of copper materials [4][5][6]. Using this pulsed radiation, fast melting with low heat dissipation is possible, which consequently increases the degree of absorption since the coefficient of absorption is dependent on the temperature.…”

Section: Welding Of Copper Materialsmentioning

confidence: 99%

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Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength

et al. 2014

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Due to the increasing electrification of automotive drives and the expansion of decentralized renewable energy generation, the consumption of copper for the fabrication of electrical components such as electric motors or conducting paths increases. To join these components, laser welding is more frequently used since it represents a flexible and fully automatable joining process. Because of the high thermal conductivity, the low absorption coefficient for infrared wavelength of common laser beam sources and the resulting limited process efficiency, welding of copper alloys represents a major challenge for laser assisted processes. In this paper, experimental investigations are presented to identify arising process limits during laser welding of pure copper materials with multi-mode fiber lasers at near infrared wavelength depending on the applied laser power and welding velocity. In addition, a potential stabilization of the welding process by shielding gas support was examined. Further investigations were focused on the influence of shielding gas on the molten pool geometry.

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Section: Variable Methodsmentioning

confidence: 99%

Section: Welding Of Copper Materialsmentioning

confidence: 99%

Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength

et al. 2014

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“…2 Absorption rates of copper, copper alloys, aluminum and steel surfaces at room temperature over the wavelength 5) Journal of Welding and Joining, Epub ahead of print , 고온균열 방지 및 기공 제어를 위해 스캐너를 이 용하여 빔을 공간적으로 모듈레이션(Spatial modulation) 하는 방법 [11][12][13] , Al 소재에 대해 빔 흡수율이 양호한 다이오드 레이저를 동시에 조사하여 예/후열 형 태의 효과를 동시에 얻는 방법 14) 등이 연구되었으며, 최 근에는 이러한 사전 연구결과에 더 나아가 멀티코어 빔 을 적용한 Al 용접 연구 15,16) 를 선보였다. [19][20][21] 나아가 최근에는 파장이 짧아 흡수 율이 비교적 양호한 그린 레이저(532 nm)를 사용하거 나, 22,23) 에너지 밀도가 매우 높은 싱글모드 레이저를 사용하는 방법 24,25) 그리고 예/후열이 가능한 멀티코어 레이저 빔을 적용하는 방법 계면에서의 저항 수치를 직접 비교하는 것보다는, 두 소재와 계면에서 측정된 저항 값을 아래의 관계식에 대 입하여 전기저항계수(k)를 도출함으로써 평가한다 33) .…”

Section: 알루미늄과 구리의 레이저 용접성unclassified

Study on Laser Welding of Dissimilar Materials between Aluminum and Copper (Ⅰ) - Research Trend in Laser Welding Technology and Materials Testing Methods -

Kim¹,

Jeong²,

Yun³

et al. 2022

J Weld Join

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In the rapidly changing automobile market, the important issues in assembling electric vehicles (EVs) can be summarized as weight reduction and battery safety. For the battery manufacturing technology, welding of dissimilar materials is crucial to assure the functionality and reliability of the battery systems installed in the recently developed EVs. This paper discusses research trends in laser welding technology for joining Al and Cu, which is currently applied for the joining process in the battery pack manufacturing. Laser welding of Al/Cu is well known to be very difficult owing to the formation of brittle intermetallic compounds as well as the low absorption rate of laser beam in both Al and Cu. Thus, the energy absorption rate, optimal energy density (beam size), welding heat input, beam modulation, and laser wavelength should be carefully optimized. The quality of dissimilar Al/Cu laser welding has been assessed by evaluating tensile and electrical properties. However, no standardized testing method exists for the laser welded materials. Therefore, standards must be urgently established for the mechanical and electrical evaluation of the laser welded materials. From the tear-down analysis of commercially produced battery modules in domestic EV, the quality of Al/Cu and Cu/Cu laser welds is critically assessed. For future research, the monitoring technology for reliable real-time laser welding should be developed for the mass-production of EV battery systems with better productivity and higher reliability.

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“…铜具有优良的导电、导热和耐腐蚀性，被广泛地应用于电气、轻工、机械制造、建筑工业、国防工业等领域。紫铜的焊接一直都是国内外学者研究的热点 [1][2][3][4][5][6] 。利用激光进行紫铜的焊接主要包括脉冲激光焊接和连续激光焊接 [7][8][9] 。当前最常用的是利用进红外波段的连续激光器进行焊接。由于铜对近红外波段激光的反射率超过 90% [10] ,连续激光器一般需要千瓦级以上才能实现铜的焊接，一方面造成能量的极大浪费，另一方面如果焊接角度控制不当，会导致反射光直接进入激光头，损伤光学系统。为了提高紫铜对激光的吸收率，很多学者尝试了不同的方法。最常见的方法是在材料表面涂上一层石墨，但石墨涂层的均匀性不好控制，导致焊缝不均匀，而且石墨会渗入到焊缝里，影响到焊接的强度 [11] 。雷玉成等 [12] 在待焊紫铜焊缝表面放置不锈钢薄片，在低激光功率下实现较大熔深的焊缝，焊缝平整美观。张晓红等 [13] 采用 300 W 的 YAG 激光在离到 87.5 HV，随着离中心位置越远，焊缝的硬度逐步降低。对于涂敷石墨的情况，焊缝中心的硬度最低，为 54.3 HV，这是由于涂敷材料的渗入影响到了焊缝的硬度。图 6 (a) 焊缝显微硬度随速度的变化情况; (b) 黑化处理与涂敷石墨焊缝硬度的对比…”

Section: 引言unclassified

Study on Copper Surface Pre-Treating and Welding with Fiber Lasers

Jiao¹,

Wang²,

Sun³

et al. 2016

激光与光电子学进展

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To improve the copper absorption coefficient to lasers, a black-treating method is proposed. With this method, the reflection coefficient of the copper to lasers with wavelength of 1064 nm can be reduced from 95% to 15.5%. The process of copper laser welding with the thickness of 0.3 mm is studied by a 500 W fiber laser machine. The shape, strength and micro-hardness of the welding seam under different welding velocity and defocus amount are analyzed and the optimum parameters are found. Moreover, the laser welding quality of copper with black-treating is compared with that with graphite coating. The results show that the micro-hardness and strength of the welding seam of copper with black-treating are better than that with graphite coating.

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Reliable Copper Spot Welding with IR Laser Radiation through Short Prepulsing

Cited by 13 publications

References 5 publications

Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength

Laser Welding of Copper Using Multi Mode Fiber Lasers at Near Infrared Wavelength

Study on Laser Welding of Dissimilar Materials between Aluminum and Copper (Ⅰ) - Research Trend in Laser Welding Technology and Materials Testing Methods -

Study on Copper Surface Pre-Treating and Welding with Fiber Lasers

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