Influence of the Application of Dry-lubricant on the Production Route for Aluminium Hang-on Parts at Volvo

An extended test program has been carried out at Volvo to determine the implications of the application of pretreated aluminium with dry lubrication. This should replace the standard route which is pressing with oil and subsequent pickling and passivation of panels. The separate results from each individual step in the production route are acceptable. However when a part is put through the whole route from pressing to assembly to paint line then it fails due to cratering after the e-coat. This is a result of incomplete removal of the dry-lubricant. To guarantee complete removal the pre-curing of the adhesives, the degreasing before phosphating and the composition of the dry-lube have to be optimized. Although pretreated aluminium with dry-lube offers great possibilities the application is at present not qualified at Volvo.