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Coarse-grained bronze-bonded diamond grinding wheels dressed using lasers and silicon carbide dressing wheels were used to grind YG8-cemented carbide workpieces. The wear patterns and grinding ratios of the laser-dressed grinding wheels were investigated after different grinding stages. After grinding, the laser-dressed grinding wheel displayed superior surface topography compared to the silicon carbide wheel, and the surface quality of the workpiece also improved. The minimum surface roughness of the workpiece was 0.425 μm. In the initial wear regime, the primary mechanisms included abrasive wear and grain removal. The grinding ratio was approximately 205.4, and the surface roughness of the workpiece after grinding was 0.314 μm. In the steady-state wear regime, abrasive wear was the primary mechanism of wearing, while minor amounts of grain removal and bond wear were observed. The grinding ratio was approximately 405.1, and the surface roughness was 0.337 μm. In the accelerated wear regime, the primary mechanisms were grain removal, abrasive wear, and bond wear. The grinding ratio was approximately 96.0, and the surface roughness was 0.454 μm. [ABSTRACT FROM AUTHOR]

Direct machining steel parts at a hardened state, known as hard turning, offers a number of potential benefits over traditional grinding in some applications. In addition, hard turning has several unique process characteristics, e.g., segmented chip formation and microstructural alterations at the machined surfaces, fundamentally different from conventional turning. Hard turning is, therefore, of a great interest to both the manufacturing industry and research community. Development of superhard materials such as polycrystalline cubic boron nitride (known as CBN) has been a key to enabling hard turning technology. A significant pool of CBN tool wear studies has been surveyed, in an attempt to achieve better processing and tooling applications, and discussed from the tool wear pattern and mechanism perspectives. Although various tool wear mechanisms, or a combination of several, coexist and dominate in CBN turning of hardened steels, it has been suggested that abrasion, adhesion (possibly complicated by tribochemical interactions), and diffusion may primarily govern the CBN tool wear in hard turning. Further, wear rate modeling including one approach developed in a recent study, on both crater and flank wear, is discussed as well. In conclusion, a summary of the CBN tool wear survey and the future work are outlined. [ABSTRACT FROM AUTHOR]