On the Importance of Measurement and Process Uncertainty in Certifying the Quality of Aluminium-Based Products

In the aluminum industry, the testing of semi-finished and finished products is the basis for consistent process management, quality control, and certification. The uncertainty of these measurements, in combination with the uncertainty of the production processes, can increase the risk of wrong decisions in closing the quality-assurance loop. This paper describes our experience of using tools such as guard bands and quality decision-support analyzers based on measurement uncertainty as well as the uncertainty of some of the most frequently used processing paths. The tools were applied to improve different stages in the production and quality certification of wrought aluminum-alloy products. Examples of the practical use of these tools when evaluating the results of chemical, mechanical, and metallographic testing and the conformity assessment of various extruded, rolled, and forged products are described. With the use of these tools, we ensure the compliance of comparative measurements and the effective reduction of costs related to quality.