Fracture wear of grinding wheels

Stress characteristics and fracture wear of brazed CBN grains in monolayer grinding wheels

“…However, a CBN grain can fracture easily under a tensile stress [34]. Thus a tensile failure criteria is suitable for the CBN grain, that is, when the maximum principal stress in the grain reaches a critical value, fracture occurs.…”

Abrasive Tools and Bonding Systems

“…Graham and Voutsadopoulos [137] presented data which supported the argument that fracture-type wear is the most important wear mechanism related to the loss of abrasive material from the grinding operation as a consequence of high stresses induced in the abrasive grit by grinding forces. Grit fracture was assumed to be caused by induced tensile stresses of relatively small magnitude.…”

“…In addition to chemical affinity, mechanical factors contribute significantly to attritious wear. When grinding carbon and alloy tool steels, the G-ratio is greatly reduced when grinding the material in its fully hardened state [137], which suggests that a mechanical effect is taking place. However, hardness is not indicative of grindability especially when the material's hardest phases are softer than the abrasive.…”

“…The wedge was assumed to be rigidly held in an infinitely strong bond. Graham and Voutsadopoulos [137] applied a tangential force of 5.4 lbs force and a normal force of 10.41 lbs force to produce a stress pattern showing lines of constant maximum shear stress (isochromatics). They applied Griffith's brittle fracture criterion to the post-processed finite element results in order to locate areas of compressive, tensile and neutral stresses within the model grit.…”

“…The hardest carbides in high-speed steels are carbides of tungsten, molybdenum and vanadium. The volume fraction, C*, of these carbides in tool steels relative to that of tungsten carbide by itself can be approximated in terms of the weight percentages of tungsten (W), molybdenum (Mo), and vanadium (V) as [137];…”