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The hardfacings reinforced by recycled (cermet inserts of machining tools) WC-Co composite particles applied by manual arc welding can be used for protection against abrasive and erosive wear. Two categories of coatings were analyzed: with and without thermal treatment (local remelting). The hardfacings were tested under abrasive (low and medium stress) and erosive (high stress) conditions. In elevated temperature erosive conditions, coatings without heat treatment have up to two times higher wear resistance than reference material. Under low-stress conditions, coatings with the finest reinforcing particle size (180–355 µm) treated with local remelting demonstrated more than 10 times higher wear resistance than reference material. The optimal reinforcement size selection depends on the application conditions (low, average, or high stress). In most test conditions, the local remelting did not provide additional improvement. A scanning electron microscope was used for the characterization of wear mechanisms. The relation between mechanical properties and wear rates was found only for some conditions. [ABSTRACT FROM AUTHOR]

Digital Image processing can be used in many areas in some way or the other from medical to satellite applications. The efficiency of the machine is reduced and substantial energy loss was observed by mechanical wear of the contacting surfaces in materials rubbing against each other. The most common test method reported in the literature is pin-on-disc wear testing. The brass material is used for this study. The images of the worn material surface were obtained from the metallurgical inverted microscope. Adaptive Otsu's global thresholding method is used as the first step of segmentation. The granulometry by opening and closing on binary image detects the wear shapes such as scars, grooves, and pits. Shape descriptors quantify the shape of the crater which is an irregular circular-shaped patch. Craters are detected by morphological filtering using standard deviation. The boundary extraction tool extracts the overall worn area and its distribution across the material surface. The results reveal that it is possible to quantify and identify the mechanism of wear by obtaining the images using a CCD camera instead of highly sophisticated instruments like scanning electron microscope or atomic field microscope (AFM) etc., by using digital image processing. [ABSTRACT FROM AUTHOR]