Laser-welded, hot-stamped door ring in 2014 Acura mdx

The world's first ultra-high-strength steel, one-piece front door stiffener ring enhances the safety performance of the Acura MDX to meet today's stringent roof crush and side impact standards. The door ring—a key part of the body structure that gives cars their strength and shape—sets a new standard in comparison with conventional multipiece, spot-weld designs. Hot-stamping manufacturing process resulted in a weight reduction of 8.6 lbs on the Acura MDX. The door ring helps the 2014 Acura MDX (V6, AWD) achieve fuel economy of 18/27 MPG city/highway.

Once the finished laser-welded blanks pass inspection, they are shipped to Magnas Cosma International operating unit in Eagle Bend, TN, where they are hot-stamped into the finished door ring before heading to Honda's production facility in Lincoln, AL, to become part of the Acura MDX. The ultimate result after hot-stamping is a lighter, stronger body structure that translates to better fuel economy and safety ratings for consumers. (841 characters)

Exercise 9. Read the following information and give an answer:

- What makes the deep penetration laserwelding attractive to car designers?

Deep Penetration Laser Welding

Deep penetration laser welding is a non-contact joining process characterized by its high focused energy density, which is capable of producing high aspect ratio (weld width : weld depth) welds in many metallic materials. It can be performed at atmospheric pressure and with a relatively low heat input, compared with inert gas arc welding processes. Deep penetration laser welding is a versatile fusion welding process, which has found wide application in industry; from spot welding of razor blades to welding of aerospace and marine structures. The process can be used to weld a variety of materials including carbon steel, stainless steel, titanium, aluminum, nickel alloys. The industrial uptake of laser welding is driven by a requirement for high volume production and/or high weld quality.

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Exercise 10. Read the following information and give an answer .

- What does theeffect of welding on various materials depend on ?

Automotive Laser Welding Applications

Whilst it is predicted that the above automotive laser welding applications will grow, there are other components and materials that will benefit from the advantages oflaser welding. Listed below are some of the topics where laser welding is poised to make an industrial impact:

- pressed components to hydroformed tubes or extrusions;

- production of tailored hydroformed tubes or other stiffened structures consisting of welded sheet;

- production of node structures in aluminum alloy castings/extrusions or extrusions/extrusions;

- welding of magnesium alloy components.

Thus, low melting point materials are easier to weld with a laser than high melting point metals. The success of these applications will ultimately depend on the weight, performance and cost advantages that can be demonstrated for high volume manufacturing scenarios.

Table 2. Metallurgical properties of materials.

Material	Comments
Aluminum 1100	welds well; no cracking problem or transformation
Aluminum 2219	no cracks; no filler metal required
Aluminum 2024/5052/6061	requires filler metal of 4047 Al to make hermetic, crack-free welds
Beryllium Copper	alloys containing higher percentages of alloying agents weld better due to lower reflectivity
Copper	high reflectivity may crease uneven welds; for material less than 0.01" thick, coating may enhance weldability
Inconel 625	some tendency for porosity in deep welds
Nickel	must be cleaned; good ductile welds and penetration
Steel, Carbon	good welds with carbon content under 0.25%; for greater carbon content, may be brittle and crack
Steel, Galvanized	severe Zn boil-off causes porosity
Steel, 300 Stainless	welds well, except 3030 and 303SE, which crack
Steel, 400 Stainless	generally welds somewhat brittle; may require pre- and post-weld heat treating
Steel, 17-4PH Stainless	needs post-weld heat treating to strengthen
Tantalum	ductile welds; special precautions against oxidation required
Tungsten	brittle welds; requires high energy

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