Quench sensitivity of 2219-T87 aluminum alloy plate

The quench sensitivity of 6.4 mm thick 2219-T87 plate was investigated by using the improved quench factor analysis method and the data of Swartzendruber et al. (NBSIR 80-2069, National Bureau of Standards, 1980). This study was exceptional for the breadth and quality of the investigations. The close integration of the quench factor analysis (QFA) with such a broad and deep independent study of commercial material, was significant in establishing awareness and credibility of QFA. The report by Swartzendruber et al., by the very breadth and depth, exposed some limitations of the QFA. The report did not include emphasizing these limitations nor attempting a remedy. The intention of the present paper is to demonstrate how the QFA can be extended to deal with the limitations implicitly exposed by Swartzendruber et al. The quench sensitivity of the alloy's yield strength was modeled by three C-curves which represented loss of solute by precipitation of (i) θ phase on grain boundaries, (ii) θ phase in the matrix, and (iii) θ′ phase on matrix dislocations, which is consistent with previous findings reported in the literature. The model and the implications of the results are discussed in the paper.