Evaluation of the cutting forces, the surface roughness, and the tool wear characteristics during machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool

In this research, we had studied the sensitivity for machining of cobalt-based superalloy Haynes 188 with ceramic cutting tool. The investigation had focused on the effects of the cutting speed, on the cutting forces, and on the surface roughness based on Taguchi’s experimental design. The effects of machining parameters were determined using Taguchi’s L27 orthogonal array. The signal-to-noise ratio was calculated for the average of surface roughness and the cutting forces, and the smaller were used to determine the optimal cutting conditions. The analysis of variance and the signal-to-noise ratio had effects on the parameters on both surface roughness and cutting. Three different types of cutting tools had been used in the experiment, namely KYON 4300, KYS 25, and KYS 30. The cutting force of Fz was considered to be the main cutting force. Depending on the material which had been used as cutting tool, the Fz had the lowest cutting speed and the lowest surface roughness with the KYS25 ceramic tool. The cutting force and the surface roughness of KYON 4300 cutting tool had shown better performance than other cutting tools. The flank wear and notch were found to be more effective in the experiments. The long chips were removed at low and medium cutting speeds, while the sawdust with one edge and narrow pitch at high cutting speeds was obtained.

Wear Performance of The Zirconia Toughened Alumina Added With TiO2 and Cr2O3 Ceramic Cutting Tool

The zirconia toughened alumina enhanced with titania and chromia (ZTA-TiO2-Cr2O3) ceramic cutting tool is a new cutting tool that possesses good hardness and fracture toughness. However, the performance of the ZTA-TiO2-Cr2O3 cutting tool continues to remain unknown and therefore requires further study. In this research, the wearing of the ZTA-TiO2-Cr2O3 cutting tool and the surface roughness of the machined surface of stainless steel 316L was investigated. The experiments were conducted where the cutting speeds range between 314 to 455 m/min, a feed rate from 0.1 to 0.15 mm/rev, and a depth of cut of 0.2 mm. A CNC lathe machine was utilised to conduct the turning operation for the experiment. Additionally, analysis of the flank wear and crater wear was undertaken using an optical microscope, while the chipping area was observed via scanning electron microscopy (SEM). The surface roughness of the machined surface was measured via portable surface roughness. The lowest value of flank wear, crater wear and surface roughness obtained are 0.044 mm, 0.45 mm2, and 0.50 µm, respectively at the highest cutting speed of 455 m/min and the highest feed rate of 0.15 mm/rev. The chipping area became smaller with the increase of feed rate from 0.10 to 0.15 mm/rev and larger when the feed rate decrease. This was due to the reduced vibrations at the higher spindle speed resulting in a more stable cutting operation, thereby reducing the value of tool wear, surface roughness, and the chipping area.