High Friction Research Articles

Static friction measurement methodology for the assessment of performance of industrial valves at high temperatures: Case study for a nickel-based alloy coating

High static friction between functional surfaces poses a serious challenge for industrial valves, particularly for those used in the advanced ultra-supercritical power generation industry that requires raising the steam temperature to 760 °C. In this context, we established the static friction measurement methodology by evaluating the effects of temperature, loading time, and number of static cycles on the evolution of the static coefficient of friction up to 800 °C. This methodology was applied on a nickel-based solid lubricant coating that appears an attractive candidate to withstand very harsh environments. The tribological behavior is explained in terms of a competition of three mechanisms governing the static friction processes: micro-welding or sintering of asperities, creep of asperities, and formation of lubricious oxides.

Yüksek Silisli Lamel Grafit Dökme Demir Kamyon Fren Disklerinin Sürtünme ve Aşınma Davranışı

In this study, the chemical compositions of high-silicon lamellar graphite cast irons commonly used in truck brake discs and the effects of applied heat treatments on their friction and wear behaviors were investigated. For this purpose, samples with two different chemical compositions (first with 2.43 C and 4.5 Si; second with 2.5 C and 4.2 Si) were produced, and homogenization annealing was applied at 900°C for 30, 45, and 60 minutes followed by air cooling. Hardness, tensile testing, and wear testing were performed on the heat-treated samples. Wear tests were conducted at room temperature and dry sliding conditions (20 N load, 250 mm sliding distance, and 200 mm/min sliding speed) using a ball-on-disk wear apparatus against 52100 bearing steel. The increase in homogenization heat treatment time resulted in an increase in hardness and tensile strength values for both lamellar graphite cast iron grades. The wear test results indicated that both the chemical composition and the duration of applied heat treatment influenced the friction coefficient and wear volume losses. Since high friction coefficient and low wear volume losses are desired in brake discs, it was determined that the best result among the compared samples was achieved in the sample produced with a chemical composition of 2.5 C and 4.2 Si, and then homogenized at 900°C for 30 minutes.

Composition, structure, and wear resistance of (TiZrNbMoTa)CxN1-x high entropy alloy carbonitride coatings prepared by reactive radio-frequency magnetron sputtering

HEN has high hardness and good toughness but a high coefficient of friction and poor wear resistance. In this study, a high hardness, toughness, and wear-resistant HECxN1-x coating was prepared by reactive radio-frequency magnetron sputtering (RFMS) technology. The phase composition, microstructure, mechanical properties, and tribological properties of the HEN and HECxN1-x coatings were investigated. The results show that all coatings have single-phase rock salt structures. The double anion lattice structure of the HECxN1-x coating produces a high lattice distortion effect and grain refinement effect, which realizes the strengthening and hardening of the coating. When the [C]/([C] + [N]) ratio is 0.3, the hardness of the HECxN1-x coating reaches the maximum value of 41.7GPa, and when the [C]/([C] + [N]) ratio is 0.4, the coating toughness reaches the maximum value of 0.91GPa, which are 48 % and 203 % higher than HEN. The self-lubricating effect of supersaturated precipitated amorphous carbon makes the HECxN1-x coating achieve excellent tribological properties. Among them, HEC0.5N0.5 coating has the best tribological properties, its coefficient of friction (COF) is 0.391, which is 148 % lower than that of HEN coating, and the wear rate is reduced to 1/15 of HEN coating, which is one order of magnitude reduction. Introducing the C element based on HEN can effectively solve the problems of high friction coefficient and poor wear resistance of high entropy nitride ceramic coatings.

Spreading ceramic stereolithography pastes: Insights from shear- and orthogonal-rheology

We study the shear rheological behavior of a commercial stereolithography paste containing ≈50 vol. % of zirconia particles (diameter ≈ 100 nm) with the aim to clarify physical mechanisms occurring during the “scraping” step of this yield stress fluid. Beyond a flow curve characterized by a high zero-shear viscosity accompanied with an overall shear-thinning behavior, we investigate in a systematic way the transient regime through start-up experiments. We demonstrate that a structural transition occurs between 10−2 and 10−1 s−1, resulting in an apparent interruption of the shear-thinning. The corresponding transient response presents a pronounced extra-growth of the shear stress before to stabilize at high strain amplitude and a negative first normal stress difference peak, both effects become stronger at higher shear rates. These observations are rationalized based on the high interparticle friction owing to the polyhedral shape and the roughness of the particles. In addition, relaxation tests following the start-up experiments reveal that the samples submitted to shear rates higher than 10−1 s−1 cannot relax the shear stress to the same level as in low shear rate experiments, suggesting a durable structural modification likely to impact the quality of the parts prior to their debinding and densification. Finally, we utilize orthogonal superposition rheology to illustrate how the application of an oscillatory deformation during the scraping procedure could help to reduce the shear-thinning interruption and improve the stereolithography processing as already observed empirically during scraping.

High friction of rubber caused by negative fluid pressure under glycerol lubrication

The friction coefficient, tread block deformation, and fluid pressure of rubber specimens at the contact interface between them and a glass plate under glycerol lubrication with different end-face corner radii of the tread blocks were experimentally measured. The friction coefficient increased as the end-face corner radius decreased. The tread blocks were deformed due to friction, and a negative fluid pressure formed at the contact interface. The friction coefficient was positively correlated with the resultant normal force of the normal load and the fluid force. Therefore, controlling the fluid pressure by changing tread blocks’ end-face corner radius will enhance their friction under lubrication.

CATHODIC PLASMA ELECTROLYTIC DEPOSITION (CPED) TECHNIQUE FOR SURFACE STRENGTHENING OF TITANIUM AND TITANIUM ALLOYS: A MINI REVIEW

Due to the unique properties of titanium (Ti) and its alloys, it has a particularly wide range of applications in aerospace, automotive, medical and other fields. However, the problems of low surface hardness, high friction coefficient and low wear resistance of Ti alloys limit its development to a certain extent. The destruction of Ti and its alloys often occurs on the surface of materials such as wear damage, corrosion, and oxidation resistance. Therefore, the exploration and application of surface strengthening technology is particularly important. The cathodic plasma electrolytic deposition (CPED) technology, as a surface modification technology, can achieve better adhesion and facilitate the material to achieve better comprehensive performance. This paper briefly introduces the basic concepts, principles and development progress of CPED. Starting from the preparation of ceramic coatings, metal coatings, diamond-like carbon films and composite coatings, it summarizes the application of CPED in Ti and its alloys. Applications in alloys to improve thermal oxidation resistance, wear resistance, corrosion resistance, and film-based adhesion. At the end, its development in the new era environment is prospected.

Functional Zwitterionic Polyurethanes: State-of-the-Art Review.

Recent advancements in bioengineering and medical devices have been greatly influenced and dominated by synthetic polymers, particularly polyurethanes (PUs). PUs offer customizable mechanical properties and long-term stability, but their inherent hydrophobic nature poses challenges in practically biological application processes, such as interface high friction, strong protein adsorption, and thrombosis. To address these issues, surface modifications of PUs for generating functionally hydrophilic layers have received widespread attention, but the durability of generated surface functionality is poor due to irreversible mechanical wear or biodegradation. As a result, numerous researchers have investigated bulk modification techniques to incorporate zwitterionic polymers or groups onto the main or side chains of PUs, thereby improving their hydrophilicity and biocompatibility. This comprehensive review presents an extensive overview of notable zwitterionic PUs (ZPUs), including those based on phosphorylcholine, sulfobetaine, and carboxybetaine. The review explores their wide range of biomedical applications, from blood-contacting devices to antibacterial coatings, fouling-resistant marine coatings, separation membranes, lubricated surfaces, and shape memory and self-healing materials. Lastly, the review summarizes the challenges and future prospects of ZPUs in biological applications.

Effect of sinusoidal pressure gradient on MHD flow of viscoelastic fluid in a channel

Unsteady Hydro Magnetic oscillatory flow of incompressible viscoelastic fluid in a channel packed with porous material is investigated under the influence of oscillatory pressure gradient. Moreover, the applied magnetic field of moderate strength interacts with electrically conducting fluid, to generate a resistive volumetric body force. In addition to it, viscoelastic fluidity, characterizing the non-Newtonian behavior in conjunction with permeability of the medium as well as sinusoidal sheared flow due to imposed favorable pressure gradient, contribute to the novelty of the study. The previous work was confined to constant motion of the lower plate but the present work includes the sinusoidal motion of the lower plate in addition to the constant motion. The importance lies with the fact that the coupling effect of sinusoidal fluctuation and viscoelastic fluidity go hard in industrial applications, particularly in process industry. The governing equations characterizing the flow are solved analytically. The striking results of this study are: the formation of inverted boundary layer in case of oscillatory lower plate with moderately escalated time span but such instability leading to flow reversal, does not appear in case of constant motion of the lower plate. Hence, it is recommended that for stability of flow and to avoid flow reversal, higher frequency of oscillation as well as larger time span is not desirable. The elastico-viscosity property reduces the volume flow rate which may be useful to control the efflux and differentiates the state of motion (resulting low skin friction) and state of rest (resulting high skin friction) in respect shearing effects at the bounding surfaces.

A methodology for setting credible speed limits based on numerical analyses and driving simulator experiments

Speed management is an integral part of the Safe System approach and tackling unsafe speeds is the first action to fix a transport system that fails to protect people. There is a consensus that where traffic speeds are a safety issue, lowering the speed limit is considered “reasonable and safe” for conditions. Nevertheless, not only should a speed limit be reasonable and safe, but it should also be credible. Otherwise, that posted speed limit is likely to be ignored. In many instances, speed limits are not credible and highway agencies still need guidance on appropriate procedures to set credible speed limits. The main objective of this study is to propose and test a novel methodology to set credible speed limits, based on the integration of the results achieved by numerical analyses and driving simulator experiments. The proposed methodology is innovative since it takes into consideration both the design characteristics of the road infrastructure according to a specific procedure as well as the drivers’ operating speeds, which are evaluated using the results of both speed prediction models and driving simulator experiments. The methodology was tested to set new speed limits on the A16 Naples–Canosa motorway, section Baiano–Candela, in southern Italy, where a posted speed limit of 80 km/h is installed in both travel directions and a new speed limit of 100 km/h is proposed, based on the results of the experiments developed within the methodology. Since the speed limit selection is associated with the expected crash frequency, the final selection of the speed limit should take into account also a safety impact assessment, considering both the expected change in the speed distribution as well as the effects of the safety countermeasures implemented in association to the speed limit change. In this study, the proposed safety countermeasures are the activation of four sections with point-to-point speed control and targeted measures at 45 curves, consisting of (1) high friction surface treatments, (2) correction of superelevation deficiencies, (3) installation of curve warning signs, chevrons, and sequential flashing beacons, and (4) shoulder rumble strips. The safety impact assessment shows that the increase in the speed limit combined with the implementation of the proposed safety countermeasures allows a crash reduction of 23%. The estimated benefit/cost ratio of the safety countermeasures is 4.66.

Research on the effect of the variation of laser power on the contour control and performance control of laser cladding Ni60CuMo/IN718 coating on RuT300

To improve the wear resistance of Vermicular cast iron (RuT300) surface and overcome the crack inhibition bottleneck of high-hardness coating, a Ni60CuMo/IN718 composite coating was fabricated on RuT300 surface. Results indicate the cracking-free coating with a maximum hardness of 475 HV0.5 at 800 W. In addition, the hard phases MC (M=Nb, Ti), Cr7C3, CrB and the self-lubricating phase Cu3.8Ni were in-situ synthesized in the coating. Increasing laser power raised C content from substrate in the molten pool, providing more C elements for in-situ synthesized Cr7C3. Along with the consumption of Cr by carbide generation, the Cr content used for in-situ synthesized CrB decreases. Moreover, the hardness of Cr7C3 is lower than that of CrB, and the low-hardness Fe in the substrate intensifies the coatings dilution with the increasing power. Therefore, these effects result in a non-positive correlation between the increase of laser power and the coatings hardness. Due to the better anti-wear effect of the high hardness coating, the hardest coatings have the lowest wear rates at room temperature (RT). Abrasive wear is the primary wear mechanism for these coatings at RT. Fe2O3 generated by high temperature friction plays a lubricating effect, but the coating with the low hardness softened by high temperature is not conducive to the compaction and forming of the oxide film. As a result, coatings that produce a moderate oxide film at 300 °C and 500 °C have a lower wear rate in the same environment. The main wear mechanism for the coatings is oxidative wear.

Mechanism of hydraulic fracture vertical propagation in deep shale formation based on elastic–plastic model

Deep shale reservoirs exhibit strong plasticity, and the simulation results from previous fracturing simulations based on elastic models may not adequately account for the effects of plastic. Therefore, the research objective is to develop a 3D finite element method (FEM) model of hydraulic fracture vertical propagation in multilayer reservoirs. The model simultaneously considering Drucker-Prager elastic–plastic rock model and bedding plane. To investigate the impact of various parameters on the vertical propagation pattern of fracture, it is crucial to consider factors such as friction angle, yield strength, interlayer strength, and vertical stress. This study quantitatively characterizes the mechanical parameters such as ground stress, matrix strength, and interface strength on hydraulic fracture morphology. Additionally, a new integrated control diagram is established to provide a comprehensive understanding of these effects. The results indicate that rocks with high friction angles and low yield strength are more resistant to cracking, and hydraulic fractures tend to have narrower fractures. Fracturing from high-strength and high-stress zones to lower zones promotes vertical fracture propagation. The high vertical stress plays a crucial role in preventing the fracturing fluid from entering the interface. Moreover, the strength of the formation interface greatly influences the vertical extension of hydraulic fractures. The bedding plane interface with a high cementation level can enhance the possibility of fracture vertical connection with multiple reservoirs. Conversely, breaking through low strength cemented interfaces in the formation can pose challenges for hydraulic fractures. The present simulation conditions determine that the fracture's ability to cross the layer depends on the ratio of interface strength to matrix strength, which should be between 0.25 and 0.5. These findings offer valuable theoretical guidance on the vertical propagation of fractures in deep multilayer fracturing.

Triboelectrification and Unique Frictional Characteristics of Germanium-Based Nanofilms.

In this study, germanium arsenide (GeAs) is investigated as apromising nanomaterial for application in triboelectric nanogenerators and green energy harvesting. The mechanical and electrical properties of mechanically exfoliated GeAs on silica substrates are evaluated through friction force microscopy and Kelvin probe force microscopy, respectively. First, it is observed that the surface potential/work function of GeAs varied with thickness. Second, thickness-dependent friction on GeAs films is found. However, the variation of friction with GeAs thickness followed an inverse trend typically observed for most other 2D material systems: larger friction is measured on thicker GeAs films. The higher friction is attributed to the higher surface potential of thicker GeAs, resulting from the accumulation of electrons on the GeAs surface that also resulted in higher adhesion between GeAs surface and the tip. Finally, history-dependent friction is observed and resulted from a continual increase in the friction force as the surface is scanned and originated from the triboelectrification of the surface. The dynamic triboelectrification behavior of thick GeAs during the scanning process is further verified and visualized by a serial experiment, where the GeAs is tribo-electrified through scanning and gradually de-electrified/discharged upon ceasing the scan.

Analisis Hambatan Samping Terhadap Tingkat Pelayanan Jalan Pada Ruas Jalan Ahmad Yani Kota Maumere

The increase in development in an area and the increase in population cause the need to pay attention to facilities and infrastructure in the field of transportation, especially roads. Maumere is the capital of the Sikka district. The increasing need of the people of Maumere City for traffic movement causes road performance to decrease because traffic movement exceeds the existing road capacity. Side friction occur on this road section because there are several offices, schools, shopping centers, and restaurants and are the route in and out of campuses, schools, shops, and markets. The purpose of the study is to determine the side friction of working days and holidays, the level of service of working days and holidays, and the effect of side friction on the level of road services. The method used in the research is quantitative based on PKJI 2014. The results of the weekday side friction analysis showed that the value of side friction reached 1,286 events/hour and included very high side friction classes and holidays showed that the side resistance factors reached 125 events/hour and included low side friction classes. The road service level value on weekdays is B and the holiday road service level value is B. The value of the side friction class on weekdays is high and the value of the road service level is B. while on holidays the value of the side friction class is very low and the value of the road service level is B.

Concentrations of particulate matter (PM2.5) and contributions of tire wear particle to PM2.5 in an indoor parking garage: Comparison with the outside and the differences according to the sampling sites

Particulate matter (PM) is increasingly affecting the social-economic development of countries. An increase in PM2.5 concentration increases susceptibility to cardiovascular and respiratory diseases and cancer. Tire wear particles (TWP) contribute to airborne PM. In the present work, we investigated the variation in the concentration of TWP of <2.5 μm in aerodynamic diameter (TWP2.5) in an indoor parking garage depending on the sampling sites. PM2.5 samples were collected at four sites in an indoor parking garage of a college campus: the entrance of the parking garage (Ent), the second floor toward the third floor (2F), the front of the parking zone on the second floor (2FP), and the third floor toward the fourth floor (3F). Each PM2.5 sampling was performed for 4 days during the fall season. The PM2.5 concentrations at the 2F and 2FP were similar to the outside PM2.5 concentrations, whereas those at the Ent and 3F were higher than the outside PM2.5 concentrations. The TWP2.5 concentrations in the indoor parking garage were 0.61–0.73 μg/m3. The differences in the TWP2.5 concentrations depending on the sampling sites were due to the differences in traffic volumes. The TWP2.5 concentration at the 2FP was higher than those at the other sampling sites owing to air stagnation and TWPs produced by the high friction when parking and exiting a car in the parking zone. The contributions of TWP2.5 to the PM2.5 concentrations were 3.9–11.7%, in the order of 2FP ≫ Ent > 3F > 2F. A good air ventilation system can be recommended to reduce TWP2.5 concentrations in indoor parking garages.

Effect of Cu addition on the tribological properties and oxidation behavior of nanomultilayered AlTiN/Cu coatings

As a soft metal, the addition of Cu has an important influence on the high-temperature tribological properties and oxidation behavior of nanomultilayered AlTiN/Cu coatings. At room temperature (RT), due to abrasive wear, the AlTiN coating exhibited a high friction coefficient of 0.97 and low wear resistance. After adding Cu layer, the friction coefficient gradually decreased to 0.59 at 18.4 at.% Cu due to the lubricating effect of soft metal Cu and CuO, and the best wear resistance was achieved at 2.9 at.% Cu. At 800 °C, the oxidation resistance sharply reduced after adding Cu layer, and exhibited oxidation delamination. At low Cu contents (≤4.5 at.%), by the inward diffusion of O, a mixed oxide layer of Al2O3, TiO2, and CuO formed. At 18.4 at.% Cu, by the outward diffusion and oxidation of Cu, double-layer oxides formed, and the top layer of CuO contributed to a low friction coefficient of 0.53, but also caused a reduce in the wear resistance.

Effect of the high temperature phase transition on the tribological behavior of atmospheric plasma sprayed AlCoCrFeNi-Bi2O3 coating

Owing to the brittleness of the body-centered cubic (BCC) structure and lack of self-lubrication, plasma-sprayed AlCoCrFeNi high-entropy alloy (HEA) coatings undergo severe abrasive wear, resulting in high friction and wear. In this study, the substrate surface temperature was increased (800 °C) to promote the phase transition from BCC to ductile FCC during spraying. As a result, the prepared AlCoCrFeNi HEA coating contained BCC and FCC phases, exhibiting a higher adhesive strength, lower friction coefficient and wear rate at room temperature (RT)–800 °C. In addition, the elevated substrate surface temperature enabled the transition of the low-temperature stable phase α-Bi2O3 to the high-temperature stable phase δ-Bi2O3. δ-Bi2O3 promoted the formation of low shear strength planes owing to its low interaction parameter and defect-fluorite structure with 25 % anionic vacancies similar to that of the Magnéli phase, which facilitated friction reduction in a wide temperature range. This study confirms that δ-Bi2O3 can effectively improve the anti-wear performance of the AlCoCrFeNi-Bi2O3 coating at RT, 200, 600 and 800 °C. However, at 400 °C, the low melting point and soft nature of the Bi2O3 weakened the mechanical strength of the coating and inhibited the construction of a solid and tough tribo-layer, resulting in a relatively high wear rate for AlCoCrFeNi-Bi2O3 coating. At 800 °C specifically, under the thermal coupling effect, δ-Bi2O3 migrated and aggregated on the worn surface with the oxidation product Al2O3 of the AlCoCrFeNi HEA matrix, and jointly promoted the formation of a compact and smooth tribo-layer with lubricating capability, which not only effectively reduced friction but also inhibited wear.

High‐entropy (Ti0.2V0.2Nb0.2Mo0.2W0.2)Si2 with excellent high‐temperature wear resistance

AbstractThe oxidation products (MoO3 and V2O5) have low melting points and tend to sublimate at high temperatures despite that MoSi2 and VSi2 may possess good self‐lubricating properties. To cope with this challenge, a high‐entropy transition metal disilicide was designed in this work in which transition metal elements that could form high melting point oxides were deliberately added. The high‐entropy (Ti0.2V0.2Nb0.2Mo0.2W0.2)Si2 (HE‐MSi2) with hexagonal structure was successfully prepared by SPS using Ti, V, Nb, Mo, W, and Si powders as the initial materials in this work. The HE‐MSi2 presents a high hardness (11.8 ± 0.4 GPa) and elastic modulus (387.2 ± 46.8 GPa). In particular, its hardness is higher than that of the corresponding disilicides. Noteworthy, HE‐MSi2 demonstrated superior wear resistance when compared to Mo‐Si‐based ceramics (such as MoSi2, Mo5Si3, and Mo5SiB2), high‐entropy carbides (such as (MoTaWVTi)C, (HfMoNbTaTi)C, and (TiVNbMoW)4.375, and traditional single‐phase ceramics (including Sialon, Si3N4, Al2O3, SiC, and ZrO2). Meanwhile, at a high temperature of 600°C, the friction coefficient and wear rate were reduced to 0.64 ± 0.05 and (1.88 ± 0.15)×106 mm3/N·m, respectively. The preferential oxidation of different elements of the HE‐MSi2 was validated through systematical characterization of composition evolution, which was dominantly impacted by high temperature and friction induction.

Application of electrical resistivity tomography and geotechnical techniques for identification and characterization of collapsible soils in Bafoussam (Western, Cameroon)

Road failure catastrophes have increased in frequency in the West Cameroon area. The collapsed soil characteristics that contribute to these phenomena in Bafoussam have been investigated using the geophysical investigation combined with geotechnical tests. The result of electrical resistivity tomography shows water conditions and heterogeneity of road foundation materials: resistivity values higher than 200 Ωm indicate dry materials, values between 30 and 200 Ωm define wet materials, and values lower than 30 Ωm indicate the very wet or water-saturated materials. These water-saturated materials can therefore move, bounded by a sliding surface of high-resistivity materials. Geotechnical properties analysis shows that these materials are clayey-sensitive water (64% clay fraction; A-7-6), very plastic (liquid limit: 46–63% plasticity limit: 29–39%), compressible, with high porosity (e > 0.8), low shear strength, and high friction angle (24–37°). The quality of foundation materials associated with high slopes (> 40°) and heavy rainfall in wet seasons (July–October) means that seepage water is the main factor responsible for the mass movement observed on the road of Western Cameroon. The construction or rehabilitation of these roads should be carried out in compliance with the natural conditions of the project site.Article highlights- 2D Electrical Resistivity Tomography method is able to determine the nature, subsurface structure and water conditions of road foundation soils.- Geotechnical test can be used to define the physical and mechanical properties of road foundation soils.- These two techniques complement each other to understand the mass movement observed on two sections of road failures caused by seepage water.

Mixing of powders under periodic shear stress: effect of initial filling level

Powder Mixing continues being of great importance in the field of particle technology because of the challenge to get homogeneous mixtures at a large scale. However, it is still moderately understood because of the complexity of designing 3D experiments that consider all the factors affecting the powder flow and powder mixing, hindering the acquisition of enough data that would provide a basic conception of powder behavior. This study involves a simple granular material mixing system of low friction that has five walls, where two of them are high friction moving walls following a cyclic function, and the others are non-friction static walls. The purpose was to create a complete set of 3D experiments of powder distribution to have a better insight into the inside mixing behavior as a function of the initial powder filling level. Experiments at different filling heights were run, obtaining the best mixing at the highest filling level. It was obtained a non-mixing zone with a triangle shape highly affected by the column particle weight. The increase of the vertical component of the resultant force produced by the acrylic motion walls causes a high momentum transfer in the x, y and z directions resulting in a decrease in the no-mixing zone. It was found an asymptotic behavior of the triangle height as a function of the initial filling height of the powders which indicates that values above a limited initial filling level will not have a significant effect on the triangle. A filling height increment of 100 % from 3.81 to 7.62 cm causes an increase in the mixing of 4.44 %. DEM simulations for mixing in the low-shear equipment were run to compare the experimental work

OPTIMIZATION EXPERIMENTAL STUDY OF MACHINING ENERGY CONSUMPTION OF ZIG-ZAG MILLING CUTTING PATH USING RSM.

Machining operations in CNC milling which remove the work material require power and energy to activate the machine components such as spindle motor, table and tool movement in order to withstand the high friction and load between tool and work material. Energy consumption during cutting operation is greatly influenced by the machining condition and parameters. This experimental research aims to investigate how energy responds to changes in the machining parameters such as depth of cut, spindle speed, and feed rate during face milling operation of CNC machine. The high-speed steel (HSS) tool with a 10mm diameter was used to face mill the 40mm x 40mm of Aluminum 6061. The design of experiment technique using Response Surface Methodology (RSM) is utilized to optimize the experimental work. Power usage and machining time were recorded for each machining process, which is then used to determine the machining energy consumption. The interaction between machining parameter and energy is comprehensively visualized using surface and contour plot. Additionally, the ANOVA analysis investigates the feed rate as the most influential parameter to the machining energy. Finally, the regression equation of machining energy is generated with reliability (R) value of 0.88 which can be used as an energy prediction model.