Determination of Mechanical Properties of M0 Copper Strips by Vickers and Brinell Hardness Values During Cold Rolling

Experimental rolling of copper strips (M0) on a 150×235 mill was carried out followed by testing of the material to determine the yield strength (deformation resistance), tensile strength (time resistance) and percent elongation, as well as measuring the Vickers hardness (HV) of the annealed (non-cold-worked) and deformed samples from the strips after cold rolling of copper (grade M0) of known chemical composition with 10 to 30% reduction. The changes in the Vickers hardness from 61 to 110 HV during strip rolling and quantitative relations between the hardness and mechanical properties of the samples obtained during tensile testing were determined experimentally. Linear equations were obtained for converting the HV hardness values to Brinell (HB) hardness values. Equations were obtained for determining the hardness values (HV and HB) based on the percent reduction of copper strips after cold rolling. The results of the tests and measurements were used to establish correlations between the mechanical properties (yield strength, ultimate strength, and percent elongation) of the metal and the Vickers (HV) and Brinell (HB) hardness values of copper strips of known chemical composition. Linear dependences for both σ_y and σ_u, as well as δ on both hardness parameters were obtained for the entire range of analyzed values. The use of the obtained data and equations at the metallurgical and machine-building plants makes it possible to determine and control the yield strength, ultimate strength, and percent elongation of sheet metal based on hardness without conducting expensive tensile testing of the samples.