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A tensile strip test has been developed for evaluating friction under conditions which simulate the stretching of sheet over the punch corner radius in forming a shallow stamping in a typical draw die. Preliminary results are presented for the aluminum alloys 5182-0, 2036-T4, 6009-T4 and 6010-T4,which are used for automotive applications. Tests were conducted with various lubrication conditions, different corner radii and with prestrained sheet. For given friction conditions, the maximum strain obtained over the face of the punch was significantly affected by small amounts of prestrain or small changes in the tensile/yield ratio of the sheet.

This paper presents the results of tests of one-piece face bars. It develops tentative guidelines for assessing the resistance of aluminum bumpers to local damage. Resistance to denting is shown to depend on the magnitude and location of the load applied, and the yield strength and thickness of the material. Cracking resistance is dependent on load applied, configuration of the bumper, location of load, tensile strength and thickness of the material. Deformation capacity of the material also appears to be of importance.

A study has been made of the various alloys for body sheet. These include the non-heat-treatable Al-Mg alloys and heat-treatable alloys of the Al-Mg-Si and Al-Cu-Mg types. Tests have shown that each alloy has a different combination of properties with no alloy excelling in all characteristics. At this stage in the development of aluminum body sheet, it would appear that the Al-Cu-Mg alloys 2036 and X5020 should be preferred over other types for general body sheet application. Where Lueder bands can be tolerated, Al-Mg alloys such as 5182 and X5085 offer an advantage of superior formability and are recommended for use as inner stiffening panels and supports.