Ductile‐Mode Material Removal of a Mica–Glass‐Ceramic

Abstract

The influence of crystal volume fraction on machining behavior was investigated for modified mica–glass‐ceramic materials that contained B2O3, Na2O, Li2O, and ZnO and had low melting temperatures. The machining behavior was characterized by drilling rate under a constant drilling force and chip morphology in a cutting test. To achieve the greatest drilling rate, an optimization volume fraction of crystalline mica (40%) had to be used; a further increase in the fraction of crystalline mica resulted in a corresponding decrease in the drilling rate. For this type of mica–glass‐ceramic, a continuous band of chips and a highly smooth cut surface could be formed during the cutting test at a high cutting velocity of 60 m/min and a depth of 1 mm. The results demonstrated that an outstanding machining behavior for glass‐ceramics can be achieved and that it can be comparable with metallic materials.

Investigation on Surface Insulation Strength of Machinable Ceramic Material under Pulsed Voltage in Vacuum

“…Though the space charge injected from the electrode can counteract part of the applied voltage, the ionic current would be enhanced by the increasing applied voltage. In the crystal the ionic current is dominant, and the ionic conductivity induced by the unique carrier can be described in Equation (1).…”

“…Recently a novel machinable ceramic is produced 1) , which provides the possibility that produces the vacuum insulator with more nice proˆle. Lower melting temperature and better drilling performance is obtained than present similar material (e.g.…”

Nano-mechanical behaviour of lithium metasilicate glass–ceramic

“…In abrasive machining, the plastically deformed material removal can produce damage-free surfaces when machining normal forces can be progressively diminished to milliNewtons per diamond grit (Bifano et al, 1991;Ma et al, 2003;Schmidt and Weigl, 2000;. For brittle materials to be machined in the ductile or plastic regime, their plastic deformation behaviour becomes very important, which can be studied using nanoindentation technique which also probes the contact hardness, H c , and the Young's modulus, E Pharr, 1992, 2004).…”

Effect of different coning angles on flashover characteristics across machinable ceramic in vacuum

“…Recently, our group has been invented a novel lowmelting temperature machinable glass ceramic (shortened as machinable ceramic, MC). Machinable ceramic can be called microcrystalline glass or glass ceramic, melted with proper glass materials by adjusting the crystal degree with heat controlling, the machinable ceramic is made to be micro crystal and glass phase voidfree complex material, and provides the possibility to produce the vacuum insulator with much better profile [11]. The micro structure, performance and manufacture method of this material is different from the traditional glass and ceramic, but it behaves the advantage of both the glass and ceramic.…”