High tool wear and poor surface quality significantly lead to high production cost in a metal cutting operation. Additionally, excessive usage of chemically contaminated coolants during machining negatively affects the operator health. To address these issues, novel surface textured tools were fabricated in the present work and assessed the machining performance of developed tools while cutting AISI 316 stainless steel material under Minimum Quantity Lubrication (MQL) by varying cutting inputs such as cutting velocity (v), feed rate (f), and depth of cut (ap). Notably, parallel grooved textured tools (PT) with MQL have shown remarkable improvements in machining performance compared to untextured tool (NT). The PT tools reduced the cutting temperature (Ct), rake wear (Wr), surface roughness (Ra), and cutting force (Fc) to maximum of 27%, 22%, 18%, and 30%, respectively, when compared to NT tool. These findings highlight the effectiveness of the proposed approach in improving machining efficiency and sustainability.
Bone grinding often causes excessive force and thermal damage due to the heterogeneous nature of bone tissue. To reduce mechanical and thermal loads in conventional bone grinding (CBG), this study proposes a laser-assisted bone grinding (LABG) method using laser ablation as surface pretreatment. A two-dimensional thermal model was established to predict ablation depth and the thermally affected layer. Constant-depth scratch tests and comparative grinding experiments were conducted to investigate surface integrity and material removal behavior. Results showed that the laser-induced groove structure reduced the tool-workpiece contact area, decreasing the average grinding force by 69.35% while maintaining temperatures below the 50 degrees C biological threshold. The laser-pretreated layer promoted brittle-dominated removal, where thermal microcracks interacted with grinding-induced cracks to facilitate fracture-based material removal. The proposed LABG method provides an effective approach for low-damage and high-efficiency bone machining in orthopedic applications.
Ti-6Al-4V alloys are widely applied in aerospace and biomedical fields; however, achieving ultra-smooth surface finishes remains challenging due to their high strength, low thermal conductivity, and poor machinability. To address these limitations, this study proposes a novel chemical magnetorheological finishing (CMRF) approach integrating an optimized slurry system with a cost-efficient dual-layer Halbach magnetic array. Among five investigated slurries, the formulation containing 2-aminonicotinic acid (2-ANA) achieved the best performance, providing a material removal rate of 1.91 mg/min and a surface roughness of 1 nm. To reduce dependence on expensive rare-earth magnets, a hybrid ferrite/NdFeB Halbach array was developed, decreasing NdFeB consumption by approximately 30% while maintaining magnetic performance comparable to conventional designs. Finite element simulations and experiments verified the enhanced magnetic field characteristics and stable abrasive interactions. The proposed process reduced surface roughness from 503 nm to 1 nm within 90 min, demonstrating an efficient and economical ultra-precision finishing strategy for Ti-6Al-4V alloys.
This study examines surface integrity in electrochemical discharge machining (ECDM) of glass under the synergistic action of ultrasonic vibration and tool rotation. The experimental setup features a precision-runout coupling between the ultrasonic horn and rotary motor, ensuring stable energy transfer. We quantitatively analyzed the roles of ultrasonic vibration, tool rotation, inter-electrode gap (IEG), and auxiliary electrode geometry. High ultrasonic amplitude and a wider IEG improved surface quality by enhancing cavitation and spark uniformity, whereas high tool rotation increased entrance hole overcut and microcracking. SEM and EDX analyses, along with Ra values, indicate that low ultrasonic vibration and a narrow IEG produce rough, uneven, and redeposited surfaces. Rectangular auxiliary electrodes provide better machining quality than circular electrodes. The findings demonstrate that the combined effect of ultrasonic vibration-assisted rotary tool in the ECDM process dictates the trade-off between depth of penetration, hole overcut, and surface finish in glass microfabrication.
This research investigates the fabrication of Al2O3/Al Functionally Graded Materials (FGMs) under high temperatures. Two designs were prepared, a six-layer gradual transitional structure and a three-layer intermediate structure. The materials were obtained using powder technology method with different sintering temperatures (1000-1300 degrees C) and sintering time (1-4 hr). Mathematical models were adopted to forecast volume fraction distributions and important thermal and mechanical properties of thermal conductivity, thermal expansion, and stress distribution. Findings indicated that the six-layer design provided significant assistance in property gradation, with Young's modulus of the material ranging between 380 and 70 GPa, thermal conductivity between 30 and 237 W/(m & centerdot;K), and hardness between 20 and 0.3 GPa along the material thickness. The stresses were linear with respect to the sintering temperature, ranging from 4.95 to 6.48 MPa at 1000-1300 degrees C. The experimental data were found to be very similar to the theoretical prediction, and the correlation coefficient was higher than 0.98. The novelty of the verified models forms a solid framework for how to optimize the FGM designs. It provides a potential application for Al2O3/Al FGMs as a good candidate material in extreme conditions such as high-temperature environments.
Enhancing the airflow through micro-gas turbine engines is essential to extending their lifespan and improving their performance. This study examines how altering the nozzle strut's design - a component that directs airflow - can aid in boosting thrust and lowering air resistance. A novel nozzle strut design was developed using numerical simulations and demonstrated a 3.5% increase in thrust over the standard design. Although standard sheet metal welding was used to create the initial prototype, the wind tunnel results differed from the computer forecasts. This occurred as a result of minor assembly-related shape problems. To address this issue, a precision milling procedure was used to create the nozzle and strut as a single unit. This strategy significantly reduced shape errors and increased surface quality, bringing the test results closer to the simulation results. The study emphasizes the need of precision production, particularly for complex-shaped parts. Even little errors can have a significant impact on performance in small engines. The effective combination of careful design and accurate manufacture demonstrates how sophisticated machining methods can help turn digital concepts into genuine, high-performance components. This method can also be utilized to produce more efficient engine components for future aerospace and energy technologies.
Preparing high manganese steel (HMS) coatings by laser wire cladding (LWC) is cost-effective and efficient, but it is prone to typical defects such as pores and cracks during the process. These defects significantly undermine the coating performance, resulting in increased maintenance costs and prolonged downtime in industrial environments. In related industries, the additional operating costs resulting from this can be as high as 15% annually. To enhance the wear-resistance of the coating, this paper conducts research by using laser surface remelting (LSR) technology as a post-treatment strengthening method. The research shows that when the scanning speed is increased from 2 mm/s to 5 mm/s, the average grain size decreases from approximately 5.2 mu m to 1.8 mu m, the hardness increases from 549 HV0.(3) to 725 HV0.(3), and the matrix remains mainly in the austenite phase. Under low scanning speed conditions, manganese evaporation can significantly reduce the stacking fault energy of the layer, induce martensitic phase transformation, and fully utilize the TWIP/TRIP cooperative strengthening mechanism, ultimately improving the wear resistance of the coating. This study confirms that LSR treatment can effectively control the microstructure, strengthening mechanism and wear-resistance of the coating, providing support for expanding the industrial application scope of LWC wear-resistant coatings.
Polymer-bonded elastic grinding wheels have emerged as a promising solution for fine-finishing operations, enabling the production of high-precision components with superior surface quality. However, their high elasticity results in a grinding behavior that differs significantly from that of conventional wheels. As a result, material removal becomes less effective and more difficult to control, which limits their industrial adoption. In this work, the critical conditions required to achieve effective material removal when using polymer-bonded elastic wheels are experimentally investigated. Results show that a minimum force and depth of cut are required to initiate material removal and ensure stable grinding performance. In addition, a new method is proposed to experimentally determine the in-process stiffness of the grinding system, enabling a more reliable prediction of grinding forces and improved control over material removal. Furthermore, a novel approach is developed to accurately set the initial wheel - workpiece contact, significantly improving positioning accuracy and reducing setting errors to below 1 mu m. These findings provide practical tools to enhance the accuracy, reliability, and productivity of fine-finishing operations with elastic grinding wheels.
This research article is an experimentally investigated for the machinability of Magnesium Alloy (AZ80) using design of experiment (DOE) technique employed to analyze the impact of three key input parameters, pulse-on-time, voltage, and discharge current on machining performance, and the experiment was performed using an in-house designed and developed, MX-ND-EDM was used with an overhead tool position as a new machining path for difficultto-access areas and better performance of the process. The objective was to enhance the MRR and minimize the TWR (Tool Wear Rate) under overhead machining conditions. Experimental results revealed that voltage had the least influence, while pulse-on-time showed a moderate effect on the performance measures. The optimized parameter combination: pulse-on-time 40 & micro;s, discharge current 10 A, voltage 50 V, achieved maximum MRR (6.216 mm3/min) and at pulse-on-time 20 & micro;s, discharge current 10 A, voltage 40 V, achieved minimum TWR (1.856 mm3/min), SEM analysis of the machined surface revealed microcracks, debris deposition, and craters. These findings provide valuable insights into the performance enhancement of MX-ND-EDM using the proposed overhead machining methodology.
Drilling of carbon fiber reinforced polymer (CFRP) laminates often generates defects that compromise structural integrity and service life. This study investigates drilling-induced damage in bidirectional woven CFRP laminates by examining the effects of machining parameters, laminate thickness, and thermal evolution. Results show that damage is mainly concentrated at the hole exit. Entrance delamination is primarily governed by feed rate, whereas exit delamination is more sensitive to cutting speed. Thinner laminates exhibit increased push-out delamination due to reduced support during tool breakthrough. Temperature analysis indicates that exit damage intensifies when the peak drilling temperature exceeds the resin glass transition temperature, promoting matrix softening and fiber-matrix debonding. ANOVA reveals that feed rate controls thrust force, torque, and entrance delamination, while cutting speed significantly affects exit delamination and maximum temperature. Increasing feed rate reduced temperature by 24%, whereas higher cutting speed increased exit delamination by 47%. These findings provide practical guidelines for minimizing drilling-induced damage in CFRP structures.
The current study is based on optimization of the process parameters of the turning operation using tungsten carbide-tipped cutting tool on the Mg-5Sn-3Zn-1Mn alloy. The input parameters that needed to be optimized were feed, depth of cut and spindle speed, taking into account the output parameters like Material Removal Rate (MRR) and Surface Roughness (SR). The experiments were formulated using Response Surface Methodology with the Box - Behnken Design. Quantitative techniques have been used to optimize machining operations by taking into account a number of goals, including maximizing material removal rates and decreasing surface roughness. Input parameters had been optimized and a mathematical model had been created. The depth of cut had the greatest influence on MRR and surface roughness, and the optimum conditions of 40 mm/min speed, 0.3 mm/rev feed, and 0.57 mm depth of cut produced the highest MRR and lowest surface roughness.
