• Title/Summary/Keyword: brazing joint

Search Result 103, Processing Time 0.021 seconds

A Study on the Resistance Welding of Metallic Sandwich Panel : Part 1 - Determination of Process Parameters (저항 용접을 이용한 금속 샌드위치 판재 접합에 관한 연구 : Part 1 - 공정변수의 선정)

  • Lee Sang-Min;Kim Jin-Beom;Na Suck-Joo
    • Journal of Welding and Joining
    • /
    • v.23 no.6
    • /
    • pp.49-54
    • /
    • 2005
  • Inner Structured and Bonded(ISB) panel, a kind of metallic sandwich panel, consists of two thin skin plates bonded to a micro-patterned inner structure. Its overall thickness is $1\~3mm$and it has attractive properties such as ultra-lightweight, high efficiency in stiffness-to-weight and strength-to-weight ratio. In many previous studies, resistance welding, brazing and adhesive bonding are studied for joining the panel. However these methods did not consider productivity, but focused on structural characteristics of joined panels, so that the joining process is very complicated and expensive. In this paper, a new joining process with resistance welding is developed. Curved surface electrodes are used to consider the productivity and the stopper is used between electrodes during welding time to maintain the shape of inner structure. Welding time, gap of electrodes and distance between welding points are selected as the process parameters. By measuring the tensile load with respect to the variation of welding time and gap of electrodes, proper welding conditions are studied. Welding time is proper between 1.5-2.5cycle. If welding time is too long, then inner structures are damaged by overheating. Gap of electrode should be shorter than threshold value fur joint strength, when total thickness of inner structure and skin plate is 3.3mm, the threshold distance is 3.0mm.

A Study on the Interfacial Bonding between AlN Ceramics and Metals: II. Effect of Mo Interlayer on the Residual Stress of AlN/Cu Joint (AlN 세라믹스와 금속간 계면접합에 관한 연구: II. AlN/Cu 접합체의 잔류응력에 미치는 Mo 중간재의 영향)

  • Park, Sung-Gye;Kim, Ji-Soon;You, Hee;Yum, Young-Jin;Kwon, Young-Soon
    • Korean Journal of Materials Research
    • /
    • v.9 no.10
    • /
    • pp.970-977
    • /
    • 1999
  • Effect of Mo interlayer on the relaxation of residual stress in AlN/Cu pint bonded by active-metal brazing method was investigated. The stress analyses by finite-element-method, the measurement of pint strength and the observation of fracture surface were carried out and their results were compared with each other. From the results of stress analysis it is confirmed that a Mo interlayer led to a shift of maximum stress concentration site from AlN/insert-metal interface$\rightarro$ insert-metal/Mo$\rightarro$Mo interlayer. Additionally, with increase of the Mo interlayer thickness the stress concentration with tensile component was separately built both at the interface of Cu/Mo and AlN/Mo. whereby the residual stress in the free surface of AlN close to the bonded interface was drastically reduced. The AlN/Mo/Cu pints with Mo interlayer thickness of above 400$\mu\textrm{m}$ showed the strengths higher than 200 MPa. upto max. 275 MPa, while the AlN/Cu pint only max. 52 MPa.

  • PDF

Analysis of Two-Way Fluid-Structure Interaction and Local Material Properties of Brazed Joints for Estimation of Mechanical Integrity (관형 열교환기의 기계적 건전성 확보를 위한 유체-고체 연성해석과 브레이징 접합부의 국부적 물성분포 분석)

  • Kang, Seok Hoon;Park, Sang Hu;Min, June Kee;Jeong, Ho Sung;Son, Chang Min;Ha, Man-Young;Cho, JongRae;Kim, Hyun Jun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.37 no.1
    • /
    • pp.9-16
    • /
    • 2013
  • Recent years have witnessed a strong need for eco-friendly and energy-efficient systems owing to global environmental problems. A heat exchanger is a well-known mechanical rig that has long been used in many energy systems. The use of a heat exchanger in an airplane engine has been attempted. In this case, the heat exchanger should be redesigned to be compact, lightweight, and highly reliable, and the issue of mechanical integrity gains importance. Therefore, in this study, we proposed a method for evaluating the mechanical integrity of a tube-type heat exchanger. A U-shaped single tube was used as an example, and its behavior and stress distribution were studied using fluid-structure interaction (FSI) analysis.