Feed Rate Research Articles

ANALYSIS OF FRICTION STIR WELDING JOINTS ON HIGH DENSITY POLYETHYLENE (HDPE) DUE TO CHANGE IN MATERIAL TEMPERATURE AND SPINDLE ROTATION

Friction stir welding (FSW) can be a solution in solving the problem of joining thermoplastic polymers which are difficult to do with fusion welding. Selection of the proper FSW connection parameters can produce optimal connection quality in HDPE material joints. In friction stir welding, the heat of welding is used to raise the temperature of the material from its initial state to the solid state temperature. If the material temperature (T0) is increased above room temperature (TRoom), while the FSW welding parameter is constant, then at a certain increase in T0 it will produce excess welding heat which results in excessive softening or even melting of the material being welded. Therefore, the material temperature setting (T0) becomes an important parameter FSW The process of connecting the HDPE plates with friction stir welding was carried out by varying the material temperature (T0 ) of TRoom, 50 0C, 75 0C and 100 0C. While the spindle rotation varies 2000 rpm and 2500 rpm. Other parameters controlled include the type of square butt joint, 5 mm HDPE plate thickness, 20 mm/min feed rate, 0.1 mm plunge depth, 20 mm tool shoulder diameter, 4.5 mm pin length and 6 mm pin diameter. The result is that the higher the spindle rotation and the material temperature during the welding process causes the FSW peak welding temperature to increase. The highest peak weld temperature was obtained at variations in material temperature (T0) 100 °C with a spindle rotation of 2500 rpm, which is 123.2 °C or 94% of the melting temperature of HDPE. The hardness of the weld nugged area is still lower than the hardness of the base material. The highest average tensile strength of the research variations was achieved at a spindle rotation speed of 2500 rpm and a material temperature of 75 °C of 16.8 MPa, higher than the average tensile strength of the base material which is 15.1 MPa.

Study on performance of machine learning models in predicting surface roughness when turning of hardened AISI 4340 steel using CERMET cutting tool

This study investigates the effectiveness of machine learning models in predicting surface roughness (Ra parameter) during the hard turning of AISI 4340 steel using CERMET cutting tools, an area with limited prior research. The experiments were conducted on a CNC lathe under dry conditions, with surface roughness measured using a profilometer. The Taguchi design of experiments was utilized to structure the data, incorporating factors such as cutting speed, feed rate, and depth of cut. Three machine learning algorithms-Linear Regression (LR), Random Forest (RF), and Support Vector Regression (SVR)-were employed to develop predictive models. The models' performance was evaluated using the root mean square error (RMSE) and R-squared (R²) metrics. The RF model demonstrated superior predictive accuracy with an RMSE of 0.0758 μm and an R² value of 0.9814 for the testing dataset. The performance of the LR model (RMSE = 0.0783 μm, R² = 0.9791) and the SVR model (RMSE = 0.0779 μm, R² = 0.9798) were close to that of the RF model. Overall, all the algorithms demonstrated good potential for model development in this study.

Сравнительная оценка накатывания роликом сплава AL6061-T6 в условиях сухого трения и в условиях смазки минимальным количеством наножидкости

Introduction. Roller burnishing is one of the most popular methods for improving the surface quality of a workpiece, increasing its wear resistance, microhardness and corrosion resistance. During the processing, the workpiece is compressed and smoothed under the pressure of hardened roller. Purpose of the work. The results of the research show that the introduction of minimum quantity lubrication (MQL) during roller burnishing makes it possible to increase the efficiency of the process by reducing friction and improving lubrication. Studies have shown that the use of nanofluids under MQL conditions improves the machining performance. However, very little attention has been paid to the roll burnishing of Al6061-T6 alloy under nano minimum quantity lubrication (NFMQL) conditions. The methods of investigation. In light of this, this study compares the performance of roll burnishing of Al6061-T6 alloy under dry friction conditions and NFMQL conditions. The microhardness, roundness, and surface roughness are evaluated, modeled, and optimized in the study by considering the cutting speed, feed rate, and number of passes. Based on the experimental results, mathematical models are established to predict the surface roughness, microhardness, and roundness deviation. Results and Discussion. The developed models of surface roughness, microhardness and roundness deviation show the R-square value higher than 0.9, which allows these models to be confidently used to predict the studied responses under dry friction conditions and under NFMQL conditions within the parameter domain selected in this work. According to this study, the machining performed in four passes at a cutting speed of 357 rpm and a tool feed of 0.17 mm/rev can obtain the lowest roundness deviation (3.514 μm), the best microhardness (130.19 HV) and the lowest surface roughness (0.64 μm). Further, the study shows that increasing the number of passes (more than four) does not lead to a significant improvement in surface roughness or microhardness. However, it leads to a slight increase in roundness deviation. Therefore, it is recommended to use a maximum of four passes during roll burnishing of Al6061-T6 aluminum alloy specimens under dry friction conditions to achieve optimal results. The obtained results imply that roller burnishing can effectively improve the overall surface quality and hardness of the workpiece. In addition, roller burnishing is regarded as an affordable method to enhance the functionality and strength of the machined parts by reducing the occurrence of surface defects such as scratches and cracks. It is found that the surface roughness decreases with the increase of the cutting speed. However, it is observed to increase under both dry friction and NFMQL conditions when the cutting speed is increased to 360–380 rpm. Moreover, it is found to decrease with the increase of the feed and the number of passes. But after three or four passes at a feed rate of 0.2–0.25 mm/rev, a noticeable increase in the surface roughness is observed. It is noticed that with the increase of the feed, the microhardness and the roundness deviation increase. In addition, as the number of passes increases, the roundness deviation decreases and the microhardness increases. The number of passes under dry friction condition and feed rate under NFMQL rolling has significant effects on the surface roughness. The cutting speed seems to have the greatest effect on the microhardness, followed by feed rate and the number of passes. On the other hand, the effect of increasing microhardness under NFMQL conditions seems to be stronger. Under dry friction condition, the cutting speed has a significant effect on the roundness deviation, and under NFMQL conditions, the feed rate has an effect.

Оценка качества и механических свойств получаемых слоев металла из низкоуглеродистой стали методом WAAM с использованием дополнительной механической и ультразвуковой обработки

Introduction. Additive manufacturing is a technology that enables three-dimensional (3D) components to be printed layer by layer according to digital models. Completely different from traditional manufacturing methods such as casting, forging, and machining, additive manufacturing is a near net shape manufacturing process that can greatly enhance design freedom and reduce manufacturing runtime. The material processing challenges in Wire and Arc Additive Manufacturing (WAAM) are related to achieving performance metrics related to geometric, physical, and material properties. Tight tolerances and stringent surface integrity requirements cannot be achieved by utilizing stand-alone AM technologies. Therefore, WAAM parts typically require some post-processing to meet requirements related to surface finish, dimensional tolerances and mechanical properties. It is therefore not surprising that the integration of AM with post-processing technologies into single and multi-setup machining solutions, commonly referred to as hybrid AM, has become a very attractive proposition for industry. The purpose of the work is to evaluate the quality and mechanical properties of the resulting metal layers of mild steel by WAAM method using additional mechanical and ultrasonic processing. Research Methods. To conduct the experiments, a set of welding equipment was used — a single-phase inverter device KEMPPI Kempomat 1701, designed for welding with wire in shielding gases. A mixture of argon and carbon dioxide (80 % argon and 20 % CO2) was used as a shielding gas. SV-08G2S (0.8 C-2 Mg-Si) wire was used as the surfacing material. A plate made of steel St3 with overall dimensions 150×100×5 mm was used as a base for surfacing. The surface of the plate before surfacing was thoroughly cleaned from the layer of oxides, oil, rust and other contaminants. For this purpose mechanical cleaning of the surface was used with BOSCH abrasive wheel with a diameter of 125 mm diameter and a grit size of 120. Before surfacing the surface of the product was degreased with white spirit. The gas flow rate was set at 8 dm3/min. To select the optimal wire feed rate and volt-ampere characteristic, surfacing was performed at each adjustment step of wire feed rate, and voltage. Mechanical statistical tensile tests, chemical composition analysis and metallographic studies were also performed. Results and Discussion. Gas porosity is a typical defect that occurs during the WAAM process and should be eliminated because it adversely affects the mechanical properties. Initially, gas porosity leads to a reduction in the mechanical strength of the part due to damage from microcrack formation. In addition, it often causes the surfaced layer to have worse fatigue properties due to the spatial distribution of different shape and size structures. In our experiments we found that a wire feed speed range of 5–6 m/min is optimal. Increasing the flow rate of shielding gas in the range of 8–14 l/min allows reducing porosity in the surfaced metal to almost zero. The mechanical properties of the surfaced beads show that the average value of yield strength after machining is higher than that of unprocessed specimens. The data obtained from these experiments are in good agreement with those reported in the literature. The presented results can be used in real WAAM technological processes.

Influence of cryogenically treated hob on surface characteristics of spur gear

ABSTRACT This work presents a comparative study of the surface characteristics of spur gears produced from cryotreated and untreated hobs at various cutting speeds and feed rates keeping constant depth of cut. Furthermore, a Taguchi Grey Relational Analysis was used to optimize the hobbing process and ANOVA was conducted to analyze the influence of studied parameters. The experimental run, for which the highest gray relational grade was obtained, was considered the optimal cutting condition. The results revealed that cryogenic treatment of the hob significantly decreased the spur gear’s flank surface roughness ( R a and R max ) and microgeometric deviations ( F a , F β , F p and F r ). The optimization results revealed that a cutting speed of 400 rpm and a feed of 8 mm/min with a cryo-treated hob produced the best surface characteristics (i.e. R a = 0.30 μ m , R max = 2.77 μ m , F a = 10.60 μ m , F β = 20.03 μ m , F p = 10.40 μ mand F r = 20.20 μ m ). This study can assist manufacturing industries in selecting suitable operating parameters for obtaining high-quality gears.

Optimization of Turning of Inconel 625 to Improve Surface Quality After Finishing Process

The process of machining the modern engineering materials, such as nickel-based superalloys, still requires improvement. This paper focuses on comparing the turning process of Inconel 625 superalloy using three types of cutting inserts to obtain the finishing process. The influence of cutting data, such as cutting speed, feed rate, and cutting depth, on the machined surface quality, surface quality were selected. The novelty of the research, described in the article, is the optimization of the machining of Inconel 625 by using the stepwise selection of parameters. The most important issue is that the stepwise method can be used in industry, where increasingly new nickel-chromium materials with more specific strength properties are used for parts.

Studying the performance of pressurized injection lubrication in drilling operations

ABSTRACT This study investigates the pressurized injection lubrication (PIL) technique for enhanced lubrication and cooling in drilling processes. Sustainable methods like Small Quantity Lubrication (SQL) and dry cutting often struggle with cooling efficiency and chip removal, particularly for hard-to-cut materials. Using flaxseed oil as the lubricant, this research compares PIL with SQL and dry cutting. Experimental results reveal that PIL reduces surface roughness by 26.8% and drilling thrust force by 10.7% compared to SQL at the highest feed rate. PIL also achieves low oil consumption (0.9 l/hr) and energy usage (<0.034 kWh), with a setup cost under 130 USD. Its design allows easy integration into existing machines, enhancing practicality. Finite Element Analysis (FEA) modeling was employed to predict thrust forces and residual stresses, with PIL showing the least residual stresses compared to SQL or dry drilling. These findings establish PIL as a cost-effective, sustainable solution for improving machining performance and addressing modern manufacturing challenges.

Experimental investigation of the friction stir welding process of AA5059 and AA7079 and prediction using fuzzy approach

Aluminum alloys AA 5059 and AA7079 have high strength, excellent weldability, and corrosion resistance, widely used in train and truck bodies, armored vehicles, and defense applications. Recent materials engineering tasks call for minimizing material weight and to achieve this objective, the solid-state joining approach of Friction stir welding (FSW) is utilized for material joining. FSW has produced sound welds with high joint strength and good ductility. This research investigates the weldability of AA5059 and AA7079 dissimilar aluminum alloys. In this FSW process, a threaded tapered cylindrical tool pin profile was selected, and welding trials were conducted at three different speeds of 500, 750, and 1000 rpm, with the 75 mm/min constant feed rate. The Taguchi L9 orthogonal array was selected to design the process parameters, that is, tool traversing speed, rotational speed, axial force, feed rate, and effect on dissimilar aluminum weld joints. The Mamdani-type fuzzy logic model predicted welded specimens’ ultimate tensile strength and yield strength. Microstructural analysis revealed that the grains in the stirring zone had undergone a full transformation into homogenous, evenly distributed, refined grains, which had a positive impact on the remarkable mechanical properties.

ASSESSMENT OF THE ROOT MEAN SQUARE DEVIATION ON SURFACES MACHINED BY HIGH-FEED TANGENTIAL TURNING

Recent advancements in machining focus on precision, efficiency, and handling harder materials, driven by sectors like aerospace and automotive. Hard machining, or processing materials over 45 HRC, presents challenges such as rapid tool wear, intense heat, and maintaining dimensional accuracy. Innovations in cutting tool materials and CNC technology have improved these processes, but tool degradation and high forces still complicate machining hardened materials. Surface roughness is a key quality metric, impacting performance factors like wear resistance and fatigue life. By optimizing cutting parameters, manufacturers aim to achieve consistent surface finishes, essential for durability in demanding applications. In this paper, the effect of the input parameters (depth of cut, feed, and cutting speed) are analysed on selected surface roughness parameters. The setup parameters were selected according to the full factorial design of experiment method. The results showed that higher feed rates resulted in rougher finishes, leading to greater spacing between profile elements and steeper surface profiles in the studied range.

Prediction and Optimization of Surface Roughness and Cutting Forces in Turning Process Using ANN, SHAP Analysis, and Hybrid MCDM Method

As manufacturing technologies advance, the integration of artificial neural networks in machining high-hardness materials and optimization of multi-objective parameters is becoming increasingly prevalent. By employing modeling and optimization strategies during the machining of such materials, manufacturers can improve surface roughness and tool life while minimizing cutting time, tool vibrations, and cutting forces. In this paper, the aim was to analyze the impact of input parameters (cutting speed, feed rate, depth of cut, and insert radius) on surface roughness and cutting forces during the machining of 90MnCrV7 using feed-forward neural network models and SHAP analysis. Afterward, multi-criteria optimization was applied to determine the optimal parameter levels to achieve minimum surface roughness and cutting forces using the modified PSI-TOPSIS method. According to the SHAP analysis, the insert radius has the most significant impact on the surface roughness and passive force, while in the multi-criteria analysis, according to ANOVA results, the insert radius has the most significant impact on all considered outputs. The results show that an insert radius of 0.8 mm, a cutting speed of 260 m/min, a feed rate of 0.08 mm, and a depth of cut of 0.5 mm are the optimal combination of input parameters.

Towards an eco-social circular economy: exploring the feasibility study of pyrolysis on agricultural feedstocks

AbstractThe agricultural sector is challenging to decarbonise due to its reliance on heavy machinery and fossil fuels, which face issues when decarbonising via methods such as electrification. However, agriculture provides opportunities to generate renewable energy via biomass sources due to their abundance within this sector. This feasibility study used a continuous auger pyrolysis system to assess how straw waste from a medium-scale arable farm could convert energy from an external electrical source into usable chemical potential. Wheat, barley, oil seed rape (OSR), and bean straw have all been processed and pyrolysed under different temperatures and auger feed rates. The syngas product was then analysed, considering its composition and the lower heating value. Results indicate that the percentage of carbon monoxide and hydrogen and the total volume of syngas increased with temperature. In addition, the syngas’ energy quantity increased despite the product’s decreasing heating value. The case study’s annual energy demand was equal to 14.4% of the 3900 GJ maximum potential contained within the syngas, and thus it can be concluded that there is potential for the application of this system towards a circular economy. The system’s cold gas, net, and electrical conversion efficiency were also assessed with maximum values of 37.1%, 30.1%, and 174.4%, respectively. Furthermore, the statistical analysis confirms high predictability for wheat, barley, bean, and OSR feedstocks, with a general linear model showing high accuracy across all.

Exploring the potential of flour, starch concentrate, and protein concentrate from Richlea lentils in the development of lentil based extruded puffs.

Lentil puffs were developed from a mixed design of varying weight fractions of lentil flour (x1), lentil starch concentrate (x2), and lentil protein concentrate (x3) using a twin-screw pilot scale extruder at a dry feed rate of 20kg/h (d.b.), a water feed rate of 2kg/h, and an extruder screw speed of 350rpm. Evaluations of the extrudate properties (expansion ratio, unit density), instrumental texture (hardness, crunchiness, and crispiness), and sensory properties (overall and texture liking, just about right (JAR), and check all that apply (CATA) were conducted, and the optimum lentil puff formulation was determined from sensory liking. Increasing x1 and x2 both increased the expansion ratio of the lentil puffs, whereas the interactions of x3 with x1 and x2 both reduced the unit density. All three formulation factors positively impacted the instrumental crunchiness and crispiness of the lentil puffs, whereas x3 had a larger impact on crunchiness, and x1 and x2 had a larger impact on crispiness. Lentil puff formulations with x3≥0.66 presented significantly lower sensory liking scores than those with x2≥0.33. The JAR test revealed that all lentil puff formulations were penalized for not having the right level of hardness, whereas the CATA test identified the crispy and crunchy attributes to positively correlate with overall and texture liking scores. The optimum lentil puff formulation was predicted from a maximum overall liking score of 6.1 and texture liking score of 6.7, to contain 50% (w/w, d.b.) of lentil starch concentrate and 25% of both lentil flour and lentil protein concentrate.

Effect of Floating and Sinking Formulated Feed on Growth and Production of GIFT Tilapia (Oreochromis niloticus) in Earthen Ponds

Tilapia farming is a significant sector in global aquaculture, with Nile tilapia (Oreochromis niloticus) being one of the most widely cultivated species. However, the continued increase in tilapia production raises concerns about genetic deterioration. This study aimed to evaluate the effects of different types of farm-made and floating feeds on the growth performance of Genetically Improved Farmed Tilapia (GIFT) tilapia in an on-farm trial (OFT) conducted in a farmer’s pond in Namakkal District, India. GIFT tilapia fingerlings with an average weight of 3.25 ± 0.15g were stocked at a density of 50,000 fingerlings/ha across three feeding treatments. In Treatment 1 (T1), fish were fed low-cost handmade feed, while Treatment 2 (T2) used TNJFU feed, and Treatment 3 (T3) involved a commercially available floating feed with 34.53% crude protein. Fingerlings were initially fed twice a day at 18% of their body weight for the first 15 days, after which the feeding rate was gradually reduced to 1.8% until harvest. Growth was measured biweekly using a measuring board and balance. Water quality parameters, including temperature, dissolved oxygen, pH, ammonia (NH3), nitrite (NO2), and nitrate (NO3) concentrations, were monitored, as these factors significantly influence fish growth, feed intake, health, and survival. Results cleared that final mean weight and weight gain were significantly (P≤0.05) better with (T3), while lower values were recorded with (T2 and T1), Feed intake was significantly decreased with (T3). FCR values were significantly better with T3 than T2 and T3. Survival rates insignificantly affected and ranged between 96 ± 0.88 (T3) and 85 ± 0.88(T2) 72± 0.58(T1). The Production and net profit showed significant differences (P &lt; 0.05) in gross production and net profit per hectare across the treatments. Treatment (T3) resulted in the highest production (7247.47 ± 9.63 kg/ha) and net profit ($203,740), followed by Treatment (T2) with 6588.88 ± 38.14 kg/ha and $195,080, and Treatment (T1) with 5354.36 ± 23.61 kg/ha and $2,567.73. Based on results obtained in this study and on the economical evaluation, it could be concluded that feeding floating pellets were better than feeding sinking other types of pellets, in addition to the increasing of protein percentage in diet was best in terms of economic efficiency compared with other treatments.

Microstructural characterisation studies on hot corrosion behaviour of YSZ/Gd2Zr2O7 based plasma spray coatings on SS316

Abstract The present study uses microstructural analysis to examine the impact of integrating the rare earth oxide Gadolinium Zirconate (Gd2Zr2O7) into the primary YSZ powder during plasma spray coating on an SS316 substrate. The ceramic coatings are formulated with two distinct concentrations: 5 wt. % Gd2Zr2O7, designated as 5GDZ, and 15 wt. % Gd2Zr2O7, designated as 15GDZ. The coating thickness was consistently maintained at a bond coating of 50 μm and a top coating of 200 μm across all coated samples by controlling relevant process parameters, including current, powder feed rate, and standoff distance. Hot corrosion tests were conducted on the samples using 50 mg/cm2 of molten salt comprising 60 wt. % V2O5 and Na2SO4 at a temperature of 700 °C for 12 h. The results indicated that YSZ and 15GDZ effectively prevented corrosion in the hot molten salt environment. The corrosive products containing YVO4 and m-ZrO2 in the YSZ and 15GDZ coating act as a passivation layer to inhibit corrosion to a certain extent. Compared to YSZ, 5GDZ shows a weight gain of 162.5 mg/cm2, 58.54% higher. However, there is no noticeable improvement in hot corrosion resistance. The 5GDZ coating exhibited the formation of thin, corrosive products. More spallation, cracks, and fractures are evident in the 5GDZ coating. The weight gain of 15GDZ is quantified at 115.32 mg/cm2, representing a 40.9% reduction compared to the 5GDZ coating. Hence, further increases in the weight of Gd2Zr2O7 were added with YSZ beyond 5 wt. % demonstrate an enhancement in hot corrosion resistance. The penetration of molten salt into the bond coating interface and substrate is completely inhibited in all three coatings, as evidenced by the SEM and EDAX analysis.

Humidity Resistant Biodegradable Starch Foams Reinforced with Polyvinyl Butyral (PVB) and Chitosan

In this study, water-insoluble, moisture-resistant starch foams were prepared using an optimized one-step extrusion-foaming process in a ZSK-30 twin screw extruder. The extrusion parameters, including temperature, screw configuration, die diameter, water content, and feeding rates, were optimized to achieve foams with the lowest density and controlled expansion. A screw configuration made up of three kneading sections was found to be the most effective for better mixing and foaming. Polyvinyl butyral (PVB) acted as a plasticizer, resulting in foams with a density of 21 kg/m3 and an expansion ratio of 38.7, while chitosan served as a nucleating agent, reducing cell size and promoting a uniform cell size distribution. The addition of PVB and chitosan reduced the moisture sensitivity of the foams, rendering them hydrophobic and water-insoluble. The contact angle increased from 0° for control foams to 101.5° for foams containing 10% chitosan and 10% PVB. Confocal laser scanning microscopy (CLSM) confirmed the migration of chitosan to the foam surface, enhancing hydrophobicity. Aqueous biodegradation tests, conducted at 30 °C in accordance with ISO 14852 standards, demonstrated that despite enhanced moisture resistance, the foams remained readily biodegradable, achieving approximately 80% biodegradation within 80 days. These modified starch foams present a sustainable solution for packaging and insulation applications that demand long-term humidity resistance.

Efficacy of micronized dosage forms of fenbendazole at bothryocephalosis of carp

The purpose of the research is to develop and test new dosage forms of fenbendazole for carp bothriocephalosis.Materials and methods. A formulation of four dosage forms based on fenbendazole has been developed. Laboratory lots of therapeutic feeds with dosage forms have been produced, the degree of fish infection with bothriocephalosis during the growing season and the efficacy of testing micronized dosage forms for carp bothriocephalosis have been established according to generally accepted methods. The efficacy of using micronized dosage forms at different feeding rates has been assessed.Results and discussion. When using four micronized dosage forms of fenbendazole in therapeutic granulated compound feeds for carp bothriocephalosis, the most effective was the therapeutic feed with a 6% micronized dosage form of fenbendazole given once at a 5% feeding rate. This dosage form of fenbendazole has shown an efficiency close to microsal, which is currently used for the treatment of bothriocephalosis in carp.

Tuning Flame Spray Pyrolysis for Variation of the Crystallite Size in Cu/ZnO/ZrO2 and its Influence on the Performance in CO2‐to‐Methanol Synthesis

AbstractCO2 hydrogenation to methanol (MeOH) is a key transformation in the Power‐to‐liquid concept, which aims to store energy in chemical energy carriers and chemicals. Cu/ZnO/ZrO2 (CZZ) shows great promise due to its enhanced stability in the presence of water, a critical by‐product when utilizing CO2‐based feedstocks. The structure‐sensitivity of this reaction, especially for particle sizes below 10 nm and in three‐component systems, remains highly debated. Herein, we systematically prepared a series of CZZ catalysts by flame spray pyrolysis (FSP) to vary the crystallite size and to study its effect on methanol synthesis in this three‐component system. FSP enabled us to maintain a fixed Cu/Zn/Zr ratio close to the commercial composition (61/29/10 atomic ratio), while varying the precursor feed rate. This resulted in variation in the crystallinity. The characterization by X‐ray diffraction and electron microscopy revealed an increase in crystallite size with rising feed rate for Cu and t‐ZrO2, whereas ZnO remained mostly unaffected. The testing of the materials in methanol synthesis uncovered an increase in performance, higher space time yield and MeOH selectivity, with decreasing crystallite size for two (Cu, t‐ZrO2) of its three components. The increased selectivity with smaller sizes might be attributed to an increase in interfacial sites.

Optimizing CNC turning of AISI D3 tool steel using Al₂O₃/graphene nanofluid and machine learning algorithms

Turning AISI (American Iron and Steel Institute) D3 tool steel can be challenging due to a lack of optimal process parameters and proper coolant application to achieve high surface quality and temperature control. Machine learning helps in predicting the optimal parameters, whereas nanofluids enhance cooling efficiency while preserving both the tool and the workpiece. This work intends to utilize advanced machine learning approaches to optimize process parameters with the application of hybrid nanofluids (Al2O3/graphene) during the CNC turning of AISI D3. The Response Surface Methodology (RSM), Back Propagation (BP) neural networks, and Genetic Algorithms (GA) will be utilized to model and predict optimal turning parameters to enhance surface quality and manage tool tip temperature. The experiments ranged the cutting speed, nanofluid concentration, depth of cut, and feed rate from 150 to 180 m/min, 0.3 to 0.9 wt.%, 0.5 to 0.9 mm, and 0.03-0.07 mm/rev. RSM and ANN analyses showed that cutting speed and feed rate had a significant effect on surface quality, contributing 11.5% and 10.5%, respectively, whereas the nanofluid affected tool tip temperature by 42.5%. The GA determined that the optimal cutting speed became 150 m/min, the feed rate was 0.05 mm/rev, the cutting depth was 0.6 mm, and the nanofluid concentration was 0.8%. At temperatures ranging from 23.01°C to 28.41°C, these conditions produced a desirable surface roughness of 0.16 to 0.45 μm. The findings emphasize the benefits of utilizing Al2O3/graphene nanofluid and machine learning algorithms in CNC turning to improve surface roughness and control temperature.

Machining Performance of Ti6Al4V Nano Composites Processed at Al2O3 Nano Particles Mixed Minimum Quantity Lubrication Condition

Introduction: In this research work, an attempt was made to machine Ti6Al4V nano composites utilizing Al2O3 mixed nano fluid at minimum quantity lubrication condition, in which experiments were designed using the L16 orthogonal array, whereas Material Removal Rate, Surface Roughness, machining force and power were recorded as responses. Methods: The nano composites were fabricated using the stir casting technique and the nano particles were synthesized using the sol-gel technique. the microstructure revealed that the homogeneous dispersion of particles with dendric arms. Increased cutting speed and feed lead to more tool wear, which in turn causes a decrease in surface quality and an increase in surface roughness. Results: Larger areas of cut are often the consequence of higher feed rates, which increases the amount of friction between the work piece and the cutting edge. The machining force increases when the feed rate is increased. A higher feed rate produces a large volume of the cut material in a given length of time in addition to having a dynamic impact on the cutting forces. Conclusion: It also results in a corresponding increase in the typical contact stress at the tool chip interface and in the tool chip contact zone.

Tire wear particle leachate exhibits trophic and multi-generational amplification: Potential threat to population viability

The toxic additives leached from tire wear particles (TWPs) in road runoff can directly poison aquatic organism through high-dose exposure in sporadic hotspots. Given the ubiquity of road runoff carrying TWPs, it is necessary to assess whether there are lagging effects from low-dose exposure, as the toxicity of TWPs leachate can be transferred and amplified across multi-generations and different trophic levels: microalgae, zooplankton and larval fish. In this study, Chlorella pyrenoidesa exposed to different concentrations of TWPs leachate were fed to rotifer Brachionus calyciflorus, which were subsequently used as the initial feeding for fry of Cyprinus carpio. Below 1000mg/L, the growth of microalgae was not influenced by TWPs leachate. Rotifer fed with contaminated microalgae for a single generation exhibited hormesis in their reproduction. After multigenerational feeding, the microalgae from 500mg/L treatment were sufficient to suppress reproduction of rotifer since the third generation. For the secondary consumer carp fry, survival, growth, and feeding rate were significantly inhibited at first generation when consuming the rotifers fed with microalgae exposed to 250mg/L TWPs leachate. So, evidence was presented for the generational and trophic amplification of toxicity in TWPs leachate within the food chain. A seemingly innocuous low dose can exhibit evident ecotoxicity after trophic and generational transfer, which could decline population viability of the aquatic organisms in the future.