The Influence of Cutting Parameters on Plastic Deformation and Chip Compression during the Turning of C45 Medium Carbon Steel and 62SiMnCr4 Tool Steel

The paper deals with the issue of cutting zone and chip compression. The aim was to analyse the microstructure transverse section of the cutting zone on a metallographic cut, due to determined values of chip compression and plastic deformation, which affect the cutting process efficiency. The tested cutting tool material was coated with cemented carbide. The selected workpiece materials were C45 medium carbon steel of ISO grade and 62SiMnCr4 tool steel of ISO (W.Nr. 1.2101) grade. In the experiments, a DMG CTX alpha 500 turning centre was used. The cutting speed and feed were varied, and the depth of the cut was kept constant during the turning. The plastic deformation and chip compression determine the efficiency of the cutting process. The higher compression requires more work to perform the process and, therefore, it requires more energy for doing so. With the increase of the cutting speed, the deformation for C45 steel is decreased. The rapid deformation reduction was observed when the cutting speed was increased from 145 m/min to 180 m/min. Generally, deformation is decreasing with the increase of the feed. Only at a cutting speed of 145 m/min was the deformation elevation observed, when the feed was increased from 0.4 mm to 0.6 mm. During the turning of the 62SiMnCr4 tool steel we observed an error value at a cutting speed of 145 m/min and a feed of 0.4 mm was the middle cutting parameter. However, feed dependence was clear: With an increase of the feed, the plastic deformation was decreasing. This decreasing was more rapid with the increasing of the cutting speed. Besides plastic deformation, there was analysed chip compression as well. With the increasing of the cutting speed, there was a decrease of the chip compression. Due to a lack of information in the area of the chip compression and the plastic deformation in the cutting process, we decided to investigate the cutting zone for the turning of tool steels 62SiMnCr4, which was compared with the reference steel C45. The results could be applied to increase the efficiency of the process and improvement of the surface integrity.

An Evaluation of Optimal Friction Stir Welding Factors (FSWF) For Yellow Brass 405-20

Friction stir welding (FSW) is a green, environmentally amicable, and solid-state joining technology. FSW can successfully weld a wide range of materials (similar/dissimilar parent materials) including aluminum, copper, steel, different alloys from these materials, plastics, composites. FSW of brass has already been accomplished by fewer researchers. In this research, yellow brass 405-20 is, therefore, welded with FSW that was never welded before. In this study, tool material utilized was M2 HSS that was also novel. Effect of two friction stir weld factors (FSWF), rotational speed (RS) and traverse speed (TS), was found on three output parameters i.e., weld temperature, weld strength and weld hardness. Weld temperature developed, was found to be 63.72% of melting point of base metal. A significant improvement in friction stir weld strength (FSWS) was also measured that was found to be 106.37% of the base brass strength. Finally, weld hardness was measured which was found to be 87.80% of original brass hardness. Based on main effects, optimal FSW factors were found to be 1450 rpm and 60 mm/min resulting interestingly in optimal temperature, optimal weld strength, and optimal hardness. Rotational speed (RS) was found to be significant to affect the weld temperature only at the friction stir weld zone (FSWZ) with the highest percent contribution (PCR) of 65.69%. However, PCR of transverse speed was found to be maximum for affecting weld strength as compared to its PCR towards both weld temperature and weld hardness. Current study was also deepened by microscopic investigation.

Testing Tool Material on Scratch Tester

In manufacturing industry cutting tools are considered as the backbone of the metal cutting operation. In metal cutting operation there is relative motion between the tool and the workpiece. As the tool material is harder than the workpiece material, there is deformation of the workpiece which acts as a base for the formation of chips. If we observe the process of metal cutting, we can easily find out that there is a considerable amount of heat generated during the machining operation. As there is a point of interface between the tool and the workpiece, there is absorption of generated heat into both the tool as well as work material. Due to the absorption of the heat there is distortion in the tool material. In this research article we have taken the base parameters as speed, load and stroke and the output parameter is taken as the load which breaks the coating of the tool. Keywords: tool coating, scratch tester, speed, stroke, coating.

Surface and Subsurface Quality of Titanium Grade 23 Machined by Electro Discharge Machining

Electrical Discharge Machining (EDM) is a non-traditional cutting technology that is extensively utilized in contemporary industry, particularly for machining difficult-to-cut materials. EDM may be used to create complicated forms and geometries with great dimensional precision. Titanium alloys are widely used in high-end applications owing to their unique intrinsic characteristics. Nonetheless, they have low machinability. The current paper includes an experimental examination of EDM’s Ti-6Al-4V ELI (Extra Low Interstitials through controlled interstitial element levels) process utilizing a graphite electrode. The pulse-on current (IP) and pulse-on time (Ton) were used as control parameters, and machining performance was measured in terms of Material Removal Rate (MRR), Tool Material Removal Rate (TMRR), and Tool Wear Ratio (TWR). The Surface Roughness (SR) was estimated based on the mean roughness (SRa) and maximum peak to valley height (SRz), while, the EDMed surfaces were also examined using optical and SEM microscopy and cross-sections to determine the Average White Layer Thickness (AWLT). Finally, for the indices above, Analysis of Variance (ANOVA) was conducted, whilst semi-empirical correlations for the MRR and TMRR were given using the Response Surface Method (RSM). The results show that the pulse-on time is the most significant parameter of the machining process that may increase the MRR up to 354%. Pulse-on current and pulse-on time are shown to have an impact on the surface integrity of the finished product. Furthermore, statistics, SEM, and EDX images on material removal efficiency and tool wear rate are offered to support the core causes of surface and sub-surface damage. The average microhardness of the White Layer (WL) is 1786 HV.

RESULTS OF INDUSTRIAL TESTING OF CARBIDE CUTTING TOOLS BY PULSED MAGNETIC FIELD TREATMENT AND THE EFFECT ON THE INCREASE OF THE CUTTING PROCESS EFFICIENCY

The task of increasing the efficiency of machining parts on heavy machines was determined, scientifically substantiated and solved by hardening a carbide tool the pulsed magnetic field processing (PMFP). The efficiency of machining of parts is understood as an increase in its productivity, a reduction in the cost and costs of tool materials, and an increase in instrument reliability. The working conditions of cutting tools at heavy engineering enterprises are analyzed. The wear resistance of carbide cutting tools, which have been strengthened by the PMFP, was investigated using forced test methods and modeling of the cutting process. The mechanism of changing the properties of a hard alloy under the action of a pulsed magnetic field is established. The main factors affecting the change in the wear resistance of a hard alloy under the action of a pulsed magnetic field are identified. The effect of pulsed magnetic field processing on the performance of carbide cutting tools under production conditions is investigated. The effect of hardening on productivity, cost of operation and instrumental costs is established. The interrelation of the parameters of the PMFP, the parameters of the process of machining parts and production efficiency is investigated. A statistical model has been developed that allows determining the productivity of mechanical processing depending on the properties of the tool material and the processing parameters of a pulsed magnetic field.

Writing And Reading With The Longitudinal Component of Light Using Carbazole-Containing Azopolymer Thin Films

It is well known that azobenzene-containing polymers (azopolymers) are sensitive to the polarization orientation of the illuminating radiation, with the resulting photoisomerization inducing material transfer at both the meso-and macroscale. As a result, azopolymers are efficient and versatile photonic materials, for example, they used for the fabrication of linear diffraction gratings, including subwavelength gratings, microlens arrays, and spectral filters. Here we propose to use carbazole-containing azopolymer thin films to directly visualize the longitudinal component of the incident laser beam, a crucial task for the realization of 3D structured light yet remaining experimentally challenging. We demonstrate the approach on both scalar and vectorial states of structured light, including higher-order and hybrid cylindrical vector beams. In addition to detection, our results confirm that carbazole-containing azopolymers are a powerful tool material engineering with the longitudinal component of the electric field, particularly to fabricate microstructures with unusual morphologies that differentiate from the total intensity distribution of the writing laser beam.

Determining the influence of ultra-dispersed aluminum nitride impurities on the structure and physical-mechanical properties of tool ceramics

This paper considers features related to manufacturing the chromium oxide-based tool material. The process involved ultra-dispersed powders made of aluminum nitride. It has been established that the destruction of chromium oxide at high sintering temperatures is prevented through the reaction sintering of chromium oxide (Cr2O3) and aluminum nitride (AlN). It was established that the structure of the composite depends both on the temperature and the duration of hot pressing. Thermodynamic calculations of the interaction between Cr2O3 and AlN showed that this interaction begins at a temperature of 1,300 °C. In contrast to hot pressing in the air, no СrN and Сr2N compounds were formed in a vacuum. With increasing temperature, the content of Al2O3 in solid solution becomes maximum at a temperature of 1,700 °C in the case of hot pressing in the air while in vacuum the content of Al2O3 remains unchanged within the entire temperature range of 1,300–1,700 °C. When increasing the time of hot pressing to 30 minutes, the size of individual grains reaches 10 μm. It has been shown that in the sintering process involving Cr2O3 and AlN, the plasma-chemical synthesis produces the solid solution (Cr, Al)2O3 at the interphase boundary, which improves the mechanical properties of the material. The influence exerted on the quality of the machined surface of tempered hard steel when machining by the devised tool material based on chromium oxide with an optimal admixture of 15 wt % of ultra-dispersed aluminum nitride powder was investigated. It was determined that the quality of the machined hard steel surface improved compared to standard imported tool plates. It was established that the resulting tool material, in addition to relatively high strength and crack resistance, also demonstrates high thermal conductivity, which favorably affects the quality of the machined steel surface, given that lubricants and coolants are not used during the cutting process.

EXPERIMENTAL MILLING STUDIES ON HARDENED STEELS - A REVIEW

Hardened steels have numerous applications in the construction of molds and dies due, in particular, to their outstanding thermo-mechanical characteristics, such as wear resistance and high stiffness, but especially dimensional stability at high temperatures. Machined surfaces are conditioned to have important tribological characteristics. Thus, a high quality of machined surfaces is achieved by milling processes with high cutting speeds. These types of processes even manage to replace grinding or electro-erosion machining processes with a solid electrode. The paper presents a review of experimental studies in recent years from industry and scientific research. Issues are outlined which justify the utility of machining hard metals by machining processes, with a focus on machining by milling processes. Starting from input parameters, such as technological parameters, blank material, cutting tool material and machining environment, their influence is analysed on output parameters, such as chip morphology, cutting tool wear and surface integrity.

Suitability of natural rocks as materials for cutting tools

This study presents an investigation of the usability and suitability of natural rocks as cutting tool materials. Therefore, indexable inserts are manufactured from eight different rocks and two mono minerals in this study and are used for turning of an aluminium alloy. Besides that, a characterization of the rock properties is performed. The wear of the rock tools and the surface roughness of the workpiece generated by the tools are used to evaluate their operational behaviour. Subsequently, the rock properties and the corresponding operational behaviour are used to assess the suitability of the rocks as cutting tool material. The results show that rock inserts can be used as cutting material for the turning of an aluminium alloy showing a width of wear marks between 83 and 1665 µm at the flank face after a cutting length of 500 m depending on the rock used. Furthermore, it is shown that rock tools are able to achieve surface roughness values which are comparable to those obtainable by using a conventional cemented carbide insert. The study shows that natural rocks can generally be used as alternative cutting material for the turning of aluminium. In addition a possible way for a systematic investigation and assessment of the suitability of natural rocks as cutting tool materials is presented, the relevance of the rock properties for the operational behaviour of the rock inserts is described and relevant future research topics concerning the use of rocks as cutting tool material are identified. Article highlights Demonstrating the possibility to use natural rocks as alternative environmentally friendly cutting tool material. Evaluation of operational behaviour and wear mechanisms of rock tools in turning aluminium. Identification of rock properties relevant for the operational behaviour of rock inserts.