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The fabrication of micro-textures on the chip breakers of the inserts is infrequent and examines on the combined effects of chip breakers, and surface textures of the positive rake angle inserts on chip breaking, cooling, lubrication, and friction wear are relatively scarce. In this research, a nanosecond laser was used to create textures on the insert of the chip breakers. Under wet and dry cutting environments, the cutting force, cutting heat, chip breaking, and insert wear of traditional and textured inserts were compared and analyzed. The synergistic effect of chip breaker and surface micro-texture on cutting performance is discussed. The result indicates that the combined effect of chip breaker and surface micro-textures reduces cutting forces and cutting heat, diminishes insert wear, and facilitates chip breaking. The result of this study provides an idea for an approach to the development and fabrication of high-quality inserts.

This paper investigates the influence of cutting conditions on the formation mechanism of chips using a tungsten carbide in-house lasered cutter (grooved chip breaker) and a benchmark commercial cutter during turning of AISI1040 medium carbon steel. Microstructure of the free surface and segment underside the chips are experimentally characterised via scanning electron microscopy (SEM) and white light interferometry. The mechanism of chip formation is classified into continuous, partially segmented, segmented and discontinuous. Chip breaking ability is achieved for all tested feed speeds at depth of cut above 1.2 mm, marking the transition from continuous to segmented chips. The chip breaker manufactured via a nanosecond laser proves to enable for the first time breaking of the chip below a feed rate of 0.1 mm/rev outperforming the commercial cutter and showing viability for the production capabilities of lasers for mass manufacture. Lamellae-type chips are revealed from machining using the lasered tool, while brush-stroke chips are discovered and introduced for the first time from machining using the benchmark cutter. While the lamellae form from cleavage cracks due to strain incompatibility at inclusions caused by an excess in critical shear strain. The brush-stroke chips are caused by a localised increase of temperature at the tool/material interface which lead to thermal softening of the workpiece: the resulting surface experiences large areas of plastic deformation. For the in-house lasered tool, at higher cutting speed, the shear strain hardening reduces the flow stress of the workpiece material in the shear zone.

Control of continuous chips in turning operation is a very vital issue to enhance productivity and operator safety. A famous method to control the chip size is utilization of chip breaker. In this study, the influence of different aspects of chip breaker geometry on cutting force, chip shape, and bending moment was evaluated by using finite element and experimental approaches. Therefore, cutting tests were carried out on AISI 1045 steel using tungsten carbide inserts with various chip breaker geometries. The results indicated that the predicted cutting force and chip shape are in close agreement with the experimental ones. It is also observed that the bending moment generated by the upper level of breadth surface has the highest contribution in the development of combined and nonuniform state of stress at the root and body of deformed chip. Meanwhile, the chip breaker geometry had a significant effect on the cutting force value.

The 7050 aluminum alloy is becoming more and more popular in aerospace industry, because it has good wear resistance, high strength, and high toughness while having low density. However, due to the small cutting allowance and good plastic, aluminum alloy chips are usually difficult to be broken naturally in high-speed reaming which induced the machined surface scratched. Both the tool structure and matching process parameters are the key ways to solve this problem. Different sizes of chip breaker have been analyzed by FEM simulation. Based on the FEM, three kinds of PCD reamers which have different chip breakers have been compared with the ability of chip breaking in different cutting parameters. It is found that when rotational speed is 288.8 m/min and feed rate per tooth is 0.04 mm/Z with 0.17 mm depth of chip breaker PCD reamer, the best surface quality and lowest cutting force were achieved. It is also found that the cutting force of shallow-breaker-tool (tool B) is the smallest when compared with non-breaker-tool (tool A) and deep-breaker-tool (tool C). The effect of chip breaker size on cutting force, chip curling, and surface roughness has been analyzed in both dry and wet cutting.

Ti(C,N)-based cermet turning inserts with two distinct chip breaker groove structures were employed to investigate the influence of chip breaker geometry on cutting performance. Chip removal performance and wear resistance of the inserts were evaluated according to chip morphology. The results reveal that, compared with inserts with the V-type groove, those with the SF-type groove exhibit superior chip removal capability and enhanced flank wear resistance. Based on two key parameters of the equivalent groove width and initial chip curl radius, an oblique cutting model was proposed for turning inserts with three-dimensionally complex grooves. The model incorporates the coupled effects of chip breaker geometry, workpiece material properties, inserts material properties and cutting process parameters. By controlling chip morphology, the proposed model effectively realizes the improvement and rational optimization of cutting performance, providing a theoretical basis for the design and optimization of complex groove turning inserts.

Hard machining has been recognized as an effective and efficient manufacturing process to replace the grinding of hardened material. To achieve a successful implementation of hard machining, chip morphology regulation is crucial since serrated chip morphology is desirable for breakability, collection, and automation. This study aims to address the critical factors in controlling the micro- and macro-chip morphologies in the hard turning of hardened AISI 1045 steel by using PCBN tool with chip breaker grooves to cover a wide range of machining parameters. Microscopic and macroscopic chip morphologies were measured, analyzed, and correlated with machining parameters and chip breaker. Experimental results demonstrate that high-speed machining is a substantial prerequisite for generating serrated chips by generating adiabatic shear bands and fracture bands, higher feed rate, and uncut depth are assistants to promote serrated chip when machining speed reaches its critical number. The bending force resulted from breaker grooves helps serrated chips break into 1∼3 cm lengths at macroscopic level. Periodic fluctuation of cutting forces along three directions was identified during the machining of hardened AISI 1045 steel at high machining speeds. This study suggests a feasible implementation of dry hard turning into industry applications.

Tapping process is an important machining process to produce internal threads with accuracy, quickness, and low costs. The constant study of the tapping process is necessary due to the value added to the product when the tapping step occurs. The threading operation is the last manufacturing process used in a component having one or more threaded regions. Thus, because several manufacturing processes were used before the threading process, the value added to the product is significant, and the loss of this component represents severe financial damages to the industrial sector. This work analysed the tapping process with two types of taps considering the torque and thrust force as the main response. Workpieces of SAE 1020 steel with dimensions of 122 × 22 × 20 mm were used due to its broad application in industry and mainly because this steel presents excellent machinability. The torque and thrust forces were monitored using a piezoelectric dynamometer with an acquisition rate of 600 Hz. Taps M8 with the pitch of 1.25 mm with and without chip breaker were applied in experimental tests. The initial hole was the same for all experiments with the value of 6.8 mm. The results demonstrated that torque and thrust force had a different behaviour increasing or decreasing with the change of cutting speed, type of coating, and the use or not of chip breaker. Thus, it can be concluded that taps with higher helix angle, without chip breaker, and coated were the best option for tapping in threaded blind holes.

In the metal cutting process, a blocked chip needs to be avoided as it leads to low tool life, poor machined surface quality, and large cutting force, whereas an unbroken chip may scratch the machined surface and hinder efficient chip removal in metal cutting. For finishing machining of Fe-Cr-Ni stainless steel, the chips will not be broken easily without chip breakers. Therefore, in this paper, two-dimensional (2D) finite element models of orthogonal cutting were built with finite element software, AdvantEdge, to optimize the chip breaker parameters for finishing machining of Fe-Cr-Ni stainless steel. An optimized methodology was proposed and the chip breaker was optimized based on chip curl radius, tool stress, temperature, and cutting force. The smaller groove height of chip breaker is recommended with low cutting speed and large feed rate, while the larger groove height of chip breaker is recommended with high cutting speed and small feed rate. Other chip breaker parameters were also optimized.

Laser texturing is a process that allows the selective removal of material by applying a high energy density over a small area during a very short time interval. Although it is generally common to use ultra-short pulse (ps or fs) lasers for tool engraving, in certain applications it is possible to use short pulse (ns) lasers. In this work, the material removal rate of an ns laser has been evaluated in chip-breaker milling on Al 2 O 3 cutting inserts reinforced with SiC whiskers. The results obtained show that by milling chip-breaker geometries it is possible to reduce the cutting forces, however, the process parameters used are key to obtain an adequate surface finish without embrittlement of the tool. By means of an adequate design, a reduction in cutting forces of 20% was achieved; additionally, it has been proved that there is a high dependence between tool life and the milling strategy used.

The problem of chip breaking and evacuation is the key point of staggered teeth boring and trepanning association (BTA) drilling. The factors that influence chip breaking with staggered teeth BTA deep hole drilling are analyzed by using the chip bending deformation mechanism for chip formation and flow through the rake face and chip breaker. This study investigated the distribution and variation of chip deformation and breaking along drilling conditions, with respect to drilling radius, drilling process parameters, tool wear, and chip breaker geometric parameters. The results show that the tool-chip contact length is about 1.65 times the chip thickness in staggered teeth BTA drilling. The cutting radius of the teeth has a considerable influence on the chip thickness. Compared with the drilling speed, the feed has a greater impact on chip deformation and breaking, and the chip thickness and strain increase with increased feed. Increased drilling depth and tooth wear aggravates the friction state between the chip and the rake face, augments chip thickness and tool-chip contact length, and increases the chip’s strain increment. As the width of chip breaker decreases and the height increases, the chip strain increases and the breaking conditions are improved.