Getting it together.As there is an increase in the use of assemblies consisting of different materials, there is a challenge to put these materials--say aluminum and steel--together so that there are such things as: * The required dynamic and/or static strength * Reproducibility of joints * No damage to coatings or the materials' surfaces * The possibility of automating the process. While there are some people who are deploying spot welding Spot welding A resistance-welding process in which coalescence is produced by the flow of electric current through the resistance of metals held together under pressure. Usually the upper electrode moves and applies the clamping force. or laser welding Laser welding Welding with a laser beam. The primary apparatus is the continuous-wave, convectively cooled CO2 laser with either oscillator/amplifier (gaussian output beam) or unstable resonator (hollows output beam) optics. for these tasks, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. the people from TOX TOX Total Organic Halides TOX Total Organic Halogens TOX Toxxulia Forest (Everquest) TOX Thermal Oxide TOX Tetradichlorooxylene [R]-PRESSOTECHNIK (Warrenville, IL; www.tox-us.com) there are some issues that need to be addressed with the welding processes This is a list of welding processes, separated into their respective categories. Arc welding Name Characteristics Applications Atomic hydrogen welding Two metal electrodes in hydrogen atmosphere Historical , including: [ILLUSTRATION OMITTED] * Complicated clamping fixtures * Material compatibility * Surface thermal damage * High energy requirements * High equipment investment * High maintenance requirements. Another alternative is to use rivet rivet, headed metal pin or bolt whose shaft is passed through holes in two or more pieces of metal, wood, plastic, or other material in order to unite them by forming the plain end into a second head. and screw fastening systems. Here the concerns are along the lines of: * Part preparation * Special tooling and equipment requirements * Large quantities of additional material * Appropriate material selection to avoid galvanic corrosion Galvanic corrosion is an electrochemical process in which one metal corrodes preferentially when it is in contact with a different type of metal and both metals are in an electrolyte. . Then there is the approach developed by TOX-PRESSOTECHNIK, the TOX-Round-Joint clinching system, a cold-forming process that joins two or more sheets with a simple punch-and-die combination that can be used in a manual or automatic setup. One example of where it is being used is for the hood of the Peugeot 307. The hood consists of two aluminum sheets--1-mm and 2-mm thick--and includes a 1.5-mm thick steel hood latch assembly. To produce the assembly there are four robotic units and 10 stationary units. Each of the TOX-Round-Joints formed require 80 kN of press force. Two of the guns are tasked to forming the nine 8-mm joints for attaching the latch to the hood while the balance assemble the sheets. Another application in development is being pursued by Ford at Cologne, Germany. They've conducted tests using the TOX joining system for producing wheels with two different types and thicknesses of steel: a DPW DPW n abbr (US) (= Department of Public Works) → ministerio de obras públicas 600 material 3.65-mm thick and a HR45 that's 2-mm thick. Forty wheels, size 6.5J X 16 in., are being tested for the Ford Mondeo. The joints are 12 mm in diameter and the die depth is 2.4 mm. The press force used was 150 kN. The shear strength of the joints proved to be 12,800 N and the peel strength 5,800 N. The joints proved to be equal to spot welds in bending and rolling tests on the wheels. The results of the joining process were 100% above the minimum strength values required by Ford. |
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