Experimental study on CNC engraving parameters of Afghan white jade

Abstract

The CNC machining of nephrite is increasingly used in the jade engraving industry. As the most important standard for quality evaluation, surface roughness is influenced by cutting parameters. In this paper, taking the Buddha head as the machining object, the influence of cutting parameters on the surface quality of was studied by SYIL S7 CNC milling machine. The grooving experiment was carried out at spindle speed of 24,000 rpm, then the CAXA manufacturing engineer and JDpiant software were comparatively applied in machining. Furtherly, the influence of the spindle speed on the roughness was investigated. The research results were summarized as follows: (1) No edge breakage appeared when feed speed lower than 300 mm/min with the maximum depth of cut of 0.1 mm. In this case, when the jade is machined with the spindle speed range of 16,000–24,000 rpm, the mean roughness Ra was in the range of 1,496.111–891.842 nm. (2) JDpiant software is more suitable for CNC jade engraving than CAXA manufacturing engineer. (3) In roughing stage, only the high-speed grinding contdition is satisfied, the integrity of side profile could be guaranteed. The higher spindle speed was conducive to achieve the fine surface quality. (4) The tungsten steel cutter in finish machining stage shows better grinding ability than diamond cutter used in rough machining stage. In order to formulate an economic spindle speed, the finishing surface roughness should be considered in conjunction with the requirement of polishing.