Evaluation of microhardness uncertainty components of composite material

Abstract

The study substantiates the necessity of evaluating measurement uncertainty in the context of product quality control. The evaluation of uncertainty in determining measurement accuracy provides an evidence-based approach to verifying whether the measured quality characteristic complies with established standards. The process of uncertainty evaluation in quality control is complex and labor-intensive, involving the identification of uncertainty sources, detection of correlations among input quantities, determination of probability distribution laws of influencing factors, calculation of sensitivity coefficients, as well as standard, total and expanded uncertainties. The paper presents a methodology for determining the uncertainty components in the measurement of microhardness of structural components in a composite material. Using the Ishikawa diagram, the primary sources of uncertainty were identified, including inaccuracies in the applied load, errors in the optical system, deviations in indentation diagonal measurements, and time measurement errors. The study includes an analysis of the influencing factors and provides mathematical models for estimating standard and expanded uncertainties. The proposed methodology holds practical value for testing and research laboratories engaged in the examination of mechanical properties of materials. Measurement uncertainty evaluation enables compliance with established standards, as well as control and improvement of measurement accuracy and reliability.