This paper summarizes the results of theoretical and experimental studies of tool temperatures in interrupted cutting. In the theoretical study, the temperature in a semi-infinite rectangular corner heated by a time-varying heat flux with various spatial distributions is used to investigate the general nature of the tool temperature distribution. The results of this analysis are compared with infrared and tool-chip thermocouple cutting temperature measurements from interrupted end turning tests on 2024 aluminum and gray cast iron at speeds up to 18 m/s. The results show that temperatures are generally lower in interrupted cutting than in continuous cutting under the same conditions. Temperatures depend primarily on the length of cutting cycles and secondarily on the length of cooling intervals between cycles. For short cutting cycles the peak and average surface temperatures are relatively low, but they increase rapidly as the cutting cycle is lengthened and approach steady-state values for long cycles. Temperatures increase for very short cooling intervals, since in this case heat does not disperse between heating cycles, but for moderate and large values varying the cooling interval has little effect on temperatures. The theoretical analysis reproduces the qualitative trends but underestimates temperatures for short cutting cycles. The accuracy of the analysis could be improved by using a transient model to calculate the amount of heat entering the tool from the tool-chip contact.

The developments of agricultural-based composites for structural applications such as in construction, aerospace, and automotive have gained tremendous interest from researchers due to the uniqueness of its behaviors. Among available agricultural fibers, kenaf fiber widely adopted as a reinforcement in polymer composites to form kenaf reinforced polymer matrix composites. The hybridization technique was introduced to enhance the mechanical performances of composite materials wherein two different types of reinforcements were employed to form a hybrid composite. Therefore, in this review paper, the investigations focus on the mechanical properties of kenaf hybrid composites as well as potentials and barriers of agricultural-based composites were discussed to provide a literature source for future research regarding this topic.

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The performance of zirconia toughened alumina with addition of MgO additives is investigated. Optimized composition of MgO at 1.1 wt% was used in the composition with alumina/yittria stabilized zirconia (YSZ). The composition was mixed, uniaxially pressed into rhombic 80o cutting inserts with 0.8 mm nose radius and sintered at 1600oC for 4 h in pressureless condition. For machining analysis, commercial stainless steel 316L with 12 mm diameter were used as workpiece. The workpiece was machined at 625 to 1750 rpm. Tool wear and surface roughness of workpiece were measured. Result shows three types of wear behaviour appear which are flank wear, notch wear and chipping. Flank wear and notch wear increased with the cutting speed but decrease by increasing the feedrate before increased after passing the 0.2mm/rev feedrate. While chipping very much related to the feedrate as the chipping area increased when the feedrate increased. Meanwhile, surface roughness increase with increment of cutting speed and feedrate which match the wear pattern.

The purpose of this research is to find the effects of cutting speed on the performance of the ZTA ceramic cutting tool. Three types of ZTA tools used in this study which are ZTA-MgO(micro), ZTA-MgO(nano) and ZTA-MgO-CeO2. Each of them were fabricated by wet mixing the materials, then dried at 100°C before crushed into powder. The powder was pressed into rhombic shape and sintered at 1600°C at 4 hours soaking time to yield dense body. To study the effect of the cutting speed on fabricated tool, machining was performed on the stainless steel 316L at 1500 to 2000 rpm cutting speed. Surface roughness of workpiece was measured and the tool wears were analysed by using optical microscope and Matlab programming where two types of wear measured i.e. nose wear and crater wear. Result shows that by increasing the cutting speed, the nose wear and crater wear increased due to high abrasion. However, surface roughness decreased due to temperature rise causing easier chip formation leaving a good quality surface although the tool wear is increased.

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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.