On the conversion of plastic work into heat in metals

This paper provides a comprehensive review of the methodologies employed to determine the fraction of plastic work converted into heat in the deformation of metals, known as the Taylor–Quinney coefficient (TQC). This review delves into the experimental, analytical and numerical methods found in the existing literature, highlighting their respective advantages and shortcomings, and reveals a notable variation in the reported values of the TQC of metals and how these values change with strain, strain rate, loading mode and microstructure. Despite this variation, the practice of considering the TQC as a constant between 0.85 and 0.95 is still found in the literature. The review identifies critical research gaps, emphasizing the scarcity of studies investigating the TQC at extremely high strains and strain rates. In addition, the paper highlights the interchangeability of using an integral and differential TQC without clear distinctions and the absence of objective conclusions supported by statistical significance.