• 제목/요약/키워드: Weld bead

검색결과 375건 처리시간 0.022초

자동차 이차전지 제조를 위한 알루미늄과 무산소동의 레이저 용접특성 (Laser Welding Characteristics of Aluminum and Copper Sheets for Lithium-ion Batteries)

  • 강민정;박태순;김철희;김정한
    • Journal of Welding and Joining
    • /
    • 제31권6호
    • /
    • pp.58-64
    • /
    • 2013
  • Several joining methods involving resistance welding, laser welding, ultrasonic welding and mechanical joining are currently applied in manufacturing lithium-ion batteries. Cu and Al alloys are used for tab and bus bar materials, and laser welding characteristics for these alloys were investigated with similar and dissimilar material combinations in this study. The base materials used were Al 1050 and oxygen-free Cu 1020P alloys, and a disk laser was used with a continuous wave mode. In bead-on-plate welding of both alloys, the joint strength was higher than the strength of O tempered base material. In overlap welding, the effect of welding parameters on the tensile shear strength and bead shape was evaluated. Tensile shear strength of overlap welded joint was affected by interfacial bead width and weld defect formation. The tensile-shear specimen was fractured at the heat affected zone by selecting proper laser welding parameters.

Wire Arc Additive Manufacturing(WAAM)에서 적층 비드(Bead) 형상 정확도 및 기계적 특성 향상을 위한 가변 가압장치 개발 (Development of Variable Rolling Pressure Device for Bead-Shape Accuracy and Mechanical Property Enhancement in WAAM)

  • 황예한;이춘만;김동현
    • 한국기계가공학회지
    • /
    • 제21권8호
    • /
    • pp.66-71
    • /
    • 2022
  • Metal additive manufacturing (AM) has revolutionized several manufacturing industries. AM can generate large-scale metal components and produce complex geometries close to net-shapes. WAAM is an AM technology that has garnered considerable interest among industries owing to its economics and relatively high deposition rates. However, the heat accumulation in the weld bead during deposition triggers distortion and residual stress. To address these problems, various methods of interpass pressure rolling systems have been suggested in recent research. In addition, combining the rolling and WAAM processes can mitigate residual stresses. The constant-pressure rolling of the interlayer also affect the microstructure. The coarse microstructure of the as-deposited sample was altered to finer equiaxed grains via these methods. However, the bead-shape accuracy of the interlayer constant-pressure method does not consider the heat accumulation in each layer. Therefore, this study develops an interpass variable pressure rolling system that considers the heat accumulation of each layer. The interpass variable pressure rolling system comprises deposition, detection, pressure, and transport units. Finally, verification tests are performed on the interpass variable-pressure rolling system (at 500 kg) with the WAAM process, and the obtained results are discussed.

마르텐사이트계 경화 육성용접부의 희석율 해석을 통한 Cr함량 예측에 대한 연구 (Prediction of Cr Content in the Martensitic-hardfaced Weldment Utilizing Dilution Rate Analytically Estimated)

  • 김봉훈;김춘환
    • Journal of Welding and Joining
    • /
    • 제32권6호
    • /
    • pp.14-21
    • /
    • 2014
  • High-temperature corrosion resistance of martensitic-hardfaced weldment is generally evaluated by the Cr content depending on dilution rate. Present study used a commercial program(SYSWELD) applying three-dimensional heat flow analysis to predict temperature distribution of weld. Configuration of weld bead can be determined by the contour of melting temperature and simultaneously dilution rate is calculated to predict Cr content. Experimental study also has been conducted to measure Cr content of harfaced surface welded by FCAW. Results indicated that computational results were well matched with those obtained from experiments.

Prediction of Chemical Composition of Pure Weld Metal in SAW

  • Kim Y.;Ryu D. H.;Kim J. S.;Lee B. Y.
    • International Journal of Korean Welding Society
    • /
    • 제5권1호
    • /
    • pp.10-14
    • /
    • 2005
  • An element of Pure Weld Metal(PWM) is important factor to understand the Flux's conduct in Submerged Arc Welding(SAW). To get the element of PWM, pile-up welding over than 10 layers have been used in the past. But, it took a long time to analyze the elements of PWM in this method. Therefore, in this study, instead of pile-up welding over than 10 layers, one pass bead welding is used to predict an element of PWM using mathematical formula which got to be derived. As a results that applied the formula, there was no differences between theoretical and experimental value except the element Mn and Si.

  • PDF

알루미늄 합금 용접부의 피로균열성장거동에 관한 파괴력학적 연구 (A Fracture Mechanics Study on the Fatigue Crack Growth Behaviors in Aluminum Alloy Weldments)

  • 차용훈
    • 한국생산제조학회지
    • /
    • 제5권3호
    • /
    • pp.31-39
    • /
    • 1996
  • The objective of this study is to investigate the influence of welding residual stresses on the fatigue crack growth behavior of cracks located transverse to the weld bead. For this purpose, G. T. A (Gas Tungsten Arc) welding was performed on hte Al alloy 1100-O plate and the same initial crack is made on HAZ(Heat Affected Zone), weld metal and base meta respectively. Specimens were used CT(Compact Tension) specimens. Initial welding residual stresses were measured by using strai gage sectioning method. All specimens were tested under constant amplitude load with stress ratio R=0.1, It is possible to predict fatigue crack growth behaviors and the fatigue life, using numerical analysis together with distribution of initial residual stress and the values of C and m obtained from $da/dN-{\Delta}K$

  • PDF

십자형 용접부 피로강도 산정을 위한 국부응력법의 비교연구 (A Comparative Study of the Fatigue Strength on Cruciform Joints by Local Stress Methods)

  • 양박달치;안정현
    • 대한조선학회논문집
    • /
    • 제47권4호
    • /
    • pp.573-579
    • /
    • 2010
  • The notch effects on the fatigue strength of welded joints are both stress concentration and fatigue strength reduction. In the notch stress approach, the notch effects are usually approximated by introducing weld-bead parameters for the local detailed weld joints. In this paper, well-known notch stress approaches - critical distance method, area method and fictitious rounding method are presented for the fatigue strength of cruciform joints. The estimated results of the present methods are applied to the experiments performed in this study and reported in the references. The results of the application show that the fatigue-life scatterness of the experimental data expressed in the nominal stress is significantly reduced by introducing the effective fatigue stress of the present study.

사각통 드로잉시 테일러드 블랭크의 용접선이동 및 성형성에 관한 연구 (A Study on the Weldline Movement and Formability of Tailored Blanks in Square Cup Drawing)

  • 박석완
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 1997년도 춘계학술대회논문집
    • /
    • pp.42-45
    • /
    • 1997
  • Weldline movement of tailored blanks originates from two sources, primary and secondary. Primary movement occurs by geometrical reason, that is, just scratched lines on the no-weld blanks move during drawing to be fitted to geometrical change. Secondary movement is induced by the characteristics of tailored blanks itself. The primary movement was mainly dependent on the weldline location and not affected by the type of material. The secondary movement caused by laser welding and/or small strength difference in this study was not dominant compared with primary movement. The formability of tailored blanks always inferior to those of original blanks. This is due to the existence of hardened weld bead. The closer a weldline is to punch corner where drawing is most active, the worse its formability becomes. This is because the weldline prohibits the drawing process. It was confirmed by measuring diagonal length at the blank corner. The mode of fracture was changed form wall break to draw break when the weldling was close to the punch corner.

  • PDF

AZ31 마그네슘합금 레이저 용접부의 미세조직 및 미소경도의 분포에 관한 연구 (A study on the microstructure and micro-hardenss distribution in laser welded AZ31 magnesium alloy)

  • 최영환;이목영;최시훈
    • 한국레이저가공학회지
    • /
    • 제15권3호
    • /
    • pp.11-15
    • /
    • 2012
  • The laser weld of AZ31 magnesium alloy was characterized with OM, EBSD and micros vickers hardness tester in experiment. EBSD analysis and micro-hardness measurements were carried out at the three regions (Equiaxed Zone, Columnar Dendrite Zone, Base Metal) of the welded AZ31Mg alloy sheets. The magnesium alloy show the rectangular shape bead in laser weld. EBSD analysis revealed that the three regions show the heterogeneous distribution of grain size and microtexture. Micro-hardness measurement also revealed that the heterogeneous distribution of microstructure contributed to the heterogeneous micro-hardness distribution in the three regions.

  • PDF

AI 합금 용접부의 잔류응력 및 피로강도 해석 (Analysis of the Residual Stresses and Fatigue Strenth in Aluminum Alloy Weldments)

  • 차용훈
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 1996년도 춘계학술대회 논문집
    • /
    • pp.177-182
    • /
    • 1996
  • The objective of this thesis is to investigate the influence of welding residual stresses on the fatigue growth behavior of welding residual stresses on the fatigue growth behavior of cracks located transverse to the weld bead. For this purpose, G.T.A. (Gas Tungsten Arc) welding was performed on the Al. Alloy 1100-0 plate and the same initial crack is made on HAZ(Heat Affected Zone), weld metal and base metal respectively. C.T.(Compact Tension) specimens were used as experimental material. Initial welding residual stresses were measured by using strain gage sectioning method. All specimens were tested under constant amplitude load with stress ratio R=0.1

  • PDF

선체 박판구조의 용접변형 제어에 관한 연구(II) (On the Weld-Induced Deformation Control of Ship's Thin Plate Block (II))

  • 이주성;김철호
    • 대한조선학회논문집
    • /
    • 제44권5호
    • /
    • pp.504-508
    • /
    • 2007
  • In the case of thin plate blocks, buckling deformation due to longitudinal shrinkage is the most important weld-induced deformation. This paper is concerned with developing the formula to predict the longitudinal shrinkage due to welding, in which mechanical tension effect in welding direction is accounted for. For this purpose, bead on plate welding test has been carried out for the 27 thin plate specimens with varying welding conditions and magnitude of tensile load. Empirical formula of predicting the longitudinal shrinkage has been derived based on the results of welding test, in which effect of mechanical tension is included. The derived formula can be usefully used in predicting the level of tensile load to reduce the longitudinal shrinkage.