فهرست نشریات علمی دسترسی آزاد ایران

 Ductile cast irons exhibit excellent wear resistance in frictional applications, primarily due to the inherent lubricating effect of their graphite content. In addition to graphite morphology, the matrix microstructure plays a critical role in governing wear behavior. This study evaluates the influence of various matrix structures on the dry sliding wear performance of spheroidal graphite cast iron. The specimens were produced using the in-mold spheroidizing method and cast into sand molds. To obtain different matrix types, the samples underwent a series of heat treatments, including normalizing, quenching, and austempering at 275 °C, 325 °C, and 375 °C. Microstructural characterization was carried out using optical microscopy and image analysis software. Brinell hardness testing was employed to assess mechanical properties. Dry sliding wear resistance was evaluated using a pin-on-disk tribometer, and the coefficient of friction was monitored throughout the tests. Worn surfaces and associated wear mechanisms were analyzed via scanning electron microscopy (SEM). The results indicated that the quenched sample exhibited the highest wear resistance, with a specific wear rate of 1.9 × 10⁻⁶ mm³/N.m. The normalized and austempered samples (at descending order of 275 °C, 325 °C, and 375 °C), followed by the as-cast condition, showed progressively lower performance. The dominant wear mechanism in the quenched sample was identified as a combination of oxidative wear and adhesive wear