通过关键词查论文: Cubic Boron Nitride (CBN)

文章题目页数

作者: Jing Ying Zhang, Qi Xun Yu, Si Qin Pang, Z.F. Zhu
摘要: The kinds and the properties of composite materials and superhard cutting-tool materials are introduced in this paper. By using five kinds of superhard cutting tools, such as polycrystal cubic boron nitride (PCBN), polycrystal diamond (PCD), thin film and thick film of chemical vapor deposition (CVD) diamond and carbon nitride (CxNy), two kinds of composite materials (fiber reinforced and particle reinforced) have been turned. Many experiment data have been gotten. It is shown that the superhard cutting tool is the best for machining composite materials. Moreover, surface finish and cutting force in composite material machining are discussed.
876
作者: Zhi Hong Li, H.F. Zheng, Y.M. Zhu, Q.M. Yuan
摘要: In this paper, the performances of CBN abrasives with and without Ti coatings and their changes during heat treatment were investigated under the same conditions. The results showed that the single particle compressive strength and the impact toughness for CBN abrasives with Ti coatings were lower than these of CBN abrasives without Ti coating. Ti coating on the surface of CBN abrasive particles oxidized and formed TiO2 with discontinuous structure at above 650°C during the firing process. The poor oxidation resistance of Ti coating and the discontinuous structure of its oxidation product could not protect CBN abrasives from heat damage, therefore could not improve properties of CBN abrasives.
1395
作者: Zi Cheng Li, Ai Ju Zhang, Zhi Hong Li, Yu Mei Zhu
摘要: Cubic boron nitride (cBN) grains treated with hydrochloric acid, nitric acid and sulphuric acid were investigated, respectively. The results indicated that the surface treatment technique with hydrochloric acid was an excellent method for improving the properties of cBN grains. After hydrochloric acid treating, cBN grains with clean surface and satisfied strength were obtained. Moreover, the bonding strength between cBN grains and vitrified bond was increased significantly for application in vitrified bond grinding tools.
167
作者: Eko Akhmadi, Akaishi Minoru, Tajima Itsuro
摘要: The cBN-cBN direct bonding structure of some cBN compacts made by the method of the direct conversion of the pyrolytic-BN (pBN) or wurtzite-BN (wBN) to cubic-BN at the pressure of 7GPa and temperature 2000 °C and the cBN compact made by the method of sintering the cBN powder along with polyvinylidene chloride (PVDC) at the condition of 5.5GPa and 1600 °C has been studied. The XRD, SEM, TEM analysis and the wear resistance on the ductile cast iron machining has been investigated. While the XRD analysis of the above cBN samples showed that all samples consist only of cBN, and the SEM observation showed that they all have the cBN-cBN direct bonding structure, A STEM analysis showed the existence of the impurities at the cBN crystal boundary. The starting materials and the sintering method affect the degree of these impurities.
2390
作者: R. Cai, W.B. Rowe, Michael N. Morgan
295
作者: Mohammad Rabiey, Taghi Tawakoli, K. Wegener
摘要: In many grinding applications, the material removal rate (MRR) is constrained by undesired thermal surface damages like burns and tensile residual stresses as well as dimensional inaccuracy. In dry grinding, due to lack of coolant, the limitation to achieve higher MRR is more critical as the major part of the heat, generated on the contact zone, is transferred to the workpiece. That is why the lower heat generation is a most important target by dry grinding. This paper presents some of the very interesting results by a comparison between a structured electroplated CBN wheel and a conventional one during surface grinding of steel. One of the grinding wheels has the normal structure and the other has special macro-structure topography developed for dry grinding. The results show a considerable reduction in grinding forces and less thermal damages using the novel electroplated CBN wheel comparing to conventional wheel.
119
作者: T.R.A. Pearce, D.C. Fricker, A. Speight
摘要: Electroplated CBN grinding wheels are not normally trued on a grinding machine and therefore inherently have a degree of run-out. The effect of run-out on workpiece roundness has both been modelled and measured experimentally. As well as affecting roundness, run-out can result in intermittent grinding around the wheel periphery, which can then lead to preferential wear on the most eccentric part of the wheel. This intermittent effect has been investigated by modelling the variation of the normal grinding force around the wheel and by measuring the variation of acoustic emission around the wheel during grinding tests.
483
作者: Shao Jie Lin, Yi Wu, Zheng Guang Zou, Yu Fang Shen
摘要: Selecting Si3N4 as binding agent and Al2O3–Al–Y2O3 as sintering additives, the sintered compact of polycrystalline cubic boron nitride (PcBN) was studied . By modifying the ratio of each component and the parameters of the sintering process, the compact sintered at 4.5 GPa and 1650 °C showed good mechanical properties.The phase constitution, microstructure of the sintered compact were characterized by XRD and SEM respectively. The degree of phase transformation of Si3N4 , the chemical reaction during the sintering process, and the sintering mechanism of the additives were discussed . The best relative density is more than 97 % , the flexural strength is more than 650 MPa, the Vickers hardness Hv is more than 8.7 GPa.
1191
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