Comprehensive reliability-quality integration framework for enhancing gear performance in laser powder bed fusion...

This study introduces a comprehensive framework that integrates reliability assurance and quality control in the Laser Powder Bed Fusion (L-PBF) gear manufacturing process via the Reliability-Quality-Reliability (RQR) chain model. The framework highlights the reciprocal link among manufacturing system dependability, process quality, and product reliability, hence enhancing gear performance and operating efficiency. The examination of L-PBF gears indicated that internal flaws, including absence of fusion, balling, keyhole porosity, and residual stress, significantly compromise structural integrity, while exterior issues such as surface wear, hardness variation, and geometric deviation exacerbate reliability deterioration. Experimental reliability graphs shown a significant decrease from about unity to below 0.1 during extended operation when both fault types were analyzed. The assessment of essential quality attributes verified the general stability of the process, with slight variations in wear resistance and geometric precision. Process parameters, including laser power, scan speed, and layer thickness, were recognized as critical factors affecting microstructural integrity, fatigue life, and wear reliability, while post-processing treatments like HIP markedly enhanced performance. The suggested RQR-based performance matrix offers a systematic framework for iterative process optimization and system-wide improvements, facilitating defect reduction, enhanced fatigue and wear reliability, and sustainable, high-quality manufacturing of L-PBF-manufactured gears. The framework is demonstrated using independent peer-reviewed datasets and should be interpreted as a methodological and benchmark validation rather than experimental post-process validation. Future work will focus on independent experimental verification of the proposed framework.