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Abstract

This paper presents a review of researches on CBN (cubic boron nitride) grinding wheels with the purpose of identifying the state of art in abrasive machining and serving as the basis for future researches and laboratory tests. The scientific studies investigated here report on interesting results involving grinding, published by Brazilian and foreign authors. The methods and the results are presented and discussed. In addition, a grinding setup is presented which provides more reliable experimental results about the surface integrity of fragile materials. This setup was obtained for grinding tests in several grinding conditions during the wheel service life, using alumina and vitrified and resin bond CBN grinding wheels. Results of cutting force, surface roughness and G ratio are also presented and discussed. They confirm the excellent machining capacity of the CBN wheel, with stable behavior in cutting force and roughness results during the tests. The G ratio values are in agreement with the results found by other researchers.

Magnetism and unconventional superconductivity in CenMmIn3n+2m heavy-fermion crystals

“…In many cases, the measured Hc2(0) exceeds the Pauli paramagnetic limit HP /Tc = 1.86 T/K. [32] In this regard, CeCoIn5 has been studied most extensively and, for H [001], exhibits a first order phase transition in a narrow field range at low temperatures [33], which is attributed to Pauli limiting. For H [110], a magnetically hysteretic transition develops below 0.6Tc that is consistent with the formation of a spatially inhomogeneous Fulde-Ferrel-Larkin-Ovchinnikov state.…”

Recent Progress in Precision Machining and Surface Finishing of Tungsten Carbide Hard Composite Coatings

“…The two types of grinding wheels have been largely used to grind ferrous materials, however when used on difficult-to-grind material, their cutting capacity can quickly deteriorate. Such occurrence consequently leads to higher cutting temperatures and forces, impacting the integrity of the material and the geometrical and dimensional accuracy of the part [86]. Diamond has extremely high hardness and is chemically inert making it suitable to process several hard materials including metal matrix composites and ceramic coatings such as alumina.…”