The surface quality of cemented carbide spheres directly affects their service life, sealing performance, and operational accuracy; therefore, surface quality inspection is a crucial step in production and application. Surface quality inspection primarily focuses on indicators such as defects, roughness, uniformity, and residual stress. Optical inspection is a fundamental method, using magnifying glasses or metallographic microscopes to examine macroscopic defects, while scanning electron microscopy can reveal microscopic flaws. Combined with dimensional measurements, this ensures compliance with ISO 3290 standards. Surface roughness is an important parameter; contact profilometers or optical profilometers are commonly used to measure parameters such as Ra and Rz, ensuring compliance with ASTM E1132 standards.
Non-destructive testing (NDT) is an advanced approach, including eddy current testing, X-ray diffraction, and ultrasonic scanning. Machine vision technology automatically identifies surface defects using high-resolution cameras and image processing software, achieving an accuracy of ±0.02 mm. For high-precision applications, microstructural analysis uses metallographic microscopes or SEM to observe grain size and interface bonding. To ensure inspection efficiency and quality, a tiered inspection process is recommended, with internal quality and stress state verified using NDT methods. Inspection must comply with standards such as ISO 3290 and ASTM E1132. In practice, the testing tools should be made of wear-resistant materials such as diamond, the testing should be carried out after polishing, high-precision applications require a combination of methods, and automated systems need to be calibrated regularly.
