On the Machinability for Alumina-molding Pieses (Part 1st)

Cutting condition and Roughness of Finished Surface

Abstract

In recent years, many ceramics with various kinds of properties have appeared on the market. Those ceramics are used for a few mechanical and electronic parts. The strength of alumina-ceramics piece is influenced by the residual crack of the finished surface on the green compact. The purpose of this paper is to clarify the machining performance of alumina-green compact. The machining performance of alumina-green compact is investigated and is discussed from view point of the relation between the flank wear of tool edge and the roughness of machined surface on the work-piece. In the cutting test by turning, the cutting speed was varied from 35 m/min to 150 m/min. The frequency of tool edge was measured by FFT(Fast Fourier Transform) analyzer, and worn parts of the tools were observed with the SEM and the microscope. The main results obtained are follows: (1) In the finish cutting for alumina-green compact, the best cutting condition was obtained as cutting speed of 100 m/min, feed 0.1 mm/rev, depth of cut 0.2 mm by tool of WC sintered carbide, and roughness Rmax of the machined surface was 7.10μm. (2)The tool life of this cutting was lager than other cutting. (3)The size of chip as cutting increased in proportion to the cutting length for 1/4 period of frequency on the tool edge.