Papers by Keyword: Hard Brittle Materials

Abstract: The process of micro-grinding on hard brittle glass is shown in this paper, micro-grinding equipments are designed by tools of electroplated diamond, fz(feed rate), ap (grinding depth), vg(Grinding speed) in micro-grinding brittle materials and their effects to surface quality have been discussed. It has been demonstrated that low surface roughness could be achieved by high vg and low fz. The roughness of Soda-lime glass accomplished by fz:100μm/s, ap:30μm, vg:120000rpm in the experiment is about 78nm.

Abstract: Hard brittle materials have been popular used in manufacture experience because of the excellent performances. However the low plasticity, frangibility and non-conduction make the machining very difficult. Therefore, ultrasonic vibration was introduced to common lapping for the purpose of higher removal rate and fine surface quality. The acoustic model of ultrasonic lapping was proposed, the track equations of ultrasonic lapping with different vibration modes were deduced, the influencing factors of lapping tracks were obtained, and the lapping tracks with different lapping parameters had been emulated. It can be concluded that ultrasonic lapping is a high efficient processing method adapting to ceramic materials.

Abstract: BK7 optical glass is used as the object of study in this paper. The different parameters such as lapping time, load, slurry flow, slurry concentration, abrasive grain sizes, rotating speed effect on surface roughness and material removal volume are studied. Using the way of orthogonal experiments for seeking optimization parameters to gain the smoothness surface and consume the minimum machining time. The empirical formulas of surface roughness and material removal rate are found by orthogonal test.

Abstract: . Micro ultrasonic machining (micro-USM) is an effective machining method for hard brittle materials. In the micro-USM process, the workpiece materials are machined through the accumulation of small brittle fractures generated by the impacts of abrasive grains. Therefore, it becomes difficult to obtain a smooth machined surface. In the proposed electrorheological fluid-assisted ultrasonic machining (ER fluid-assisted USM), the behavior of abrasive grains is controlled using the effect of dielectrophoretic force acting on the abrasive grains and the ER effect. The behavior of the abrasive grains can be controlled by changing the electric field distribution. In the present paper, the shape and position of the auxiliary electrode are arranged in order to control the abrasive grains to the side surface of the micro rectangular tool. By positioning the auxiliary electrode parallel to the micro rectangular tool, it becomes possible to concentrate abrasive grains to the side surface of the micro rectangular tool. Smoothing of the side surface of the workpiece by using the side surface of the micro rectangular tool is then investigated. As a result, the surface roughness of the side surface of the workpiece can be improved.