Effects of residual Ni60 spray particles on structured-blue-light scanning accuracy of helical gears

Residual unmelted alloy particles left after laser cladding severely interfere with structured blue-light scanning for helical gear remanufacturing, resulting in incomplete surface data and distorted geometric measurements in actual production. This study prepared 20CrMnTi helical gear specimens in three steps with varying particle coverage levels and conducted comparative scanning experiments. Real-time images were captured for real-time scanning to observe surface optical changes, while surface completeness, mesh retention, and surface curvature deviation were calculated to evaluate the scanning performance. Experimental results revealed that both scattered and clustered particles triggered scanning defects, and built-in software processing could not fully eliminate errors caused by heavy contamination. A combined pre-scanning solution that included air cleaning, exposure adjustment, and multi-angle scanning was proposed. After treatment, the overall scanning quality of heavily contaminated gears improved significantly. The measurement indicators returned to levels close to those of the clean samples. This study provides reliable technical support for the standardized 3D measurement of laser-cladded gears in industrial remanufacturing practice.