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This paper explains the reflectance characteristics of anodized aluminum and describes the finishing treatments which produce the desired low glow appearance required by The Proposed Federal Motor Vehicles Safety Standards. Certain of these low gloss producing treatments are easily incorporated into existing finishing lines and in many cases are more economical to apply than the present bright specular finish. The materials and processes used to satisfy this proposed standard are discussed fully.

Two new aluminum alloys, 6009 and 6010, for auto body sheet are described and technical data are presented. The 6XXX-series alloys are ideal for body sheet in several respects, providing excellent corrosion resistance, improved spot weldability, and freedom from Luder's lines, together with favorable response to aging in many paint bake cycles. The result is a combination of excellent formability in the T4 temper and, after aging, higher strength than achievable in any other aluminum alloy system having other characteristics desired in body sheet. The latter translates to excellent dent resistance, superior even to that of steel. Furthermore, scrap loop problems are eliminated; compatible alloys 6009 and 6010 may be used together to obtain optimum strength and formability without any penalties in scrap utilization. Forming, aging, finishing, and joining data for these alloys are presented.

Draw bead simulator tests were performed on various tool materials using aluminum alloys 2008-T4 and 6111-T4. The tool materials included hardened cast steel J435/0050A, D2 alloy, cast steel with ion nitride and PVD chromium nitride surface treatments, and cast steel with standard chromium and Wearalloy™ chromium coatings. Friction and galling behavior were monitored over an extended period of testing which allowed differentiation of the tool materials and alloys. Wearalloy™ and CrN tool coatings consistently demonstrated improved ability to prevent material transfer for both aluminum alloys, in spite of friction coefficients which were higher than the uncoated and ion nitrided tools. The ion nitrided surface exhibited the lowest friction coefficients of the surface treatments tested, but showed appreciably more wear. For a given lubricant and dilution ratio, alloy 2008-T4 exhibited an increased tendency for material transfer compared to alloy 6111-T4 for all tool materials tested.

This paper describes work conducted to understand the process mechanisms which cause electrode deterioration and inconsistent weld quality when welding aluminum auto body sheet. Surface objectives were found to be different at the outer and inner surfaces of the sheet. Various surface treatments were investigated and compared to arrive at an optimum treatment. Best overall results were obtained with a conversion coated inner surface and an arc-cleaned outer surface applied immediately before welding. Results were verified with an extended life test which produced more than 7,000 welds without a dud.

IN WELDBONDING, a joint is produced by (a) spotwelding through an uncured adhesive bondline or (b) flowing adhesive by capillary action into the bond area after spotwelding. Weldbonding can offer higher joint strength, reduced joint weight, improved fatigue life and, in some aircraft-oriented investigations, showed reduced manufacturing costs(1,2). Although weldbonding has had repeated use in the Russian aircraft industry(3,4), it has not been widely employed in American manufacturing to date. The most intensive efforts to develop the process have resulted from contracts sponsored by the U. S. Air Force(4). The only aluminum alloys used in these investigations were the high strength aircraft alloys and the emphasis was to develop the highest strength weldbond joints with economics a secondary consideration. These studies usually included the use of special surface treatments on the aluminum, special adhesives, and carefully controlled curing conditions.