Μm Roughness Research Articles

A grey relational analysis of the micro arc oxidation process parameters and their effects on Ti-6Al-7Nb coating performance and corrosion resistance for biomedical uses

Abstract In current investigation micro arc oxidation of Ti6Al7Nb alloy was done to improve its surface properties and corrosion resistance. Mixture of Na2SiO3, Na3PO412H2O and KOH is used as electrolyte. MAO treated Ti6Al7Nb specimens were examined using x-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) to examine their morphology and phase composition. It was observed that electrolyte composition is simultaneously included in the growing oxide layer during MAO process. From electrochemical study it was found that corrosion resistance of the Ti6Al7Nb increases during EIS testing in 0.9% NaCl solution. It was found that frequency, duty cycle, current and processing time effect the surface roughness, thickness, hardness and corrosion resistance of coating. Out of above mention parameters frequency and duty cycle has major impact on performance parameters. The objective of current investigation is to find out effects MAO process parameters on coating performance parameters such as coating thickness, hardness, surface roughness and corrosion resistance. At duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min, highest coating thickness 32.96 μm and surface roughness 3.3680 μm was obtained. Process parameters have the influence on pore size, biggest average pore size 3.8519 μm was obtained at duty cycle of 50%, frequency 500 Hz, current 300 mA and processing duration 7.5 min. Grey relational analysis is done to determine which process variable has the most influence on performance parameters. From grey relational analysis technique, it was observed that duty cycle 50%, frequency 500 Hz, current 300 mA, and processing time 7.5 min are ideal process parameters for higher coating thickness, hardness, surface roughness and better corrosion resistance. From grey relation analysis it was also found that frequency has most significant impact on performance parameters after that duty cycle, then current and at last processing time.

Role of wall roughness on the energy performance for a mixed flow pump with tip clearance

Abstract This study delves into the intricate influence of wall roughness on the mixed flow pump energy performance, particularly focusing on the simultaneous presence of tip clearance. Utilizing a well-performing mixed flow pump with a tip clearance of 0.8 mm as the subject of investigation, the research employs numerical simulation at different roughness to comprehensively analyse the effects of wall roughness on pump head, efficiency, and cavitation performance. The numerical simulation employs the SST k-ω model and the equivalent sand-gain roughness model to simulate the turbulent flow account for wall roughness. The findings discerned that both head and efficiency are inversely related to wall roughness, with decrements amplified at elevated flow rates. Notably, the ‘hump’ in head performance near 60% of the design flow rate is significantly influenced by roughness beyond 31.6μm. Additionally, efficiency exhibits a minor uptick at 0.56μm roughness before a subsequent decline. The study also highlights the multifaceted impact of roughness on the internal flow structures, including vortex and cavitation patterns. These insights emphasize the importance of balancing roughness levels to enhance energy efficiency and cavitation resistance, crucial for the practical application and long-term reliability of such machinery.

Effect of mixing-ratio and current on Mo-Cu-WC-Si coating via EDC

The present study investigates the influence of the mixing ratio of copper (Cu) and molybdenum (Mo) powders in Mo-Cu-WC-Si composite powder metallurgy (P/M) briquettes on the performance of coatings produced on Al-2014 alloy using electrical discharge coating. Three mixing ratios of Cu and Mo are selected during briquette preparation, by varying Cu in 5 wt.% decrements and Mo in 5 wt.% increments: 50Cu:30Mo, 45Cu:35Mo, and 40Cu:40Mo, with fixed 15WC:5Si. The results indicate that even a 5 wt.% variation of copper significantly affects the coating output responses. At 3 A current the 50Cu:30Mo combination shows lowest roughness of 2.4 μm, followed by 3.2 μm, and 5.4 μm roughness with 45Cu:35Mo and 40Cu:40Mo. Coating with 50Cu:30Mo ratio shows the highest wear reduction, achieving a 3-fold decrease compared to the uncoated Al-2014. Furthermore, coated samples depict a 42% reduction in corrosion rate compared to uncoated sample. Experimental results suggest that the briquette with a higher copper percentage (50 wt.%) provides a more suitable coating.

Analysis and optimization of microchannel array precision grinding processes with micro-structured micro-grinding tool

Micro-grinding has been widely used in aerospace and other industry. However, the small diameter of the micro-grinding tool has limited its machining performance and efficiency. In order to solve the above problems, micro-structure has been applied on the micro-grinding tool. A morphology modeling has been established in this study to characterize the surface of micro-structured micro-grinding tool, and the grinding performance of micro-structured micro-grinding tool has been analyzed through undeformed chip thickness, abrasive edge width, and effective distance between abrasives. Then deviation analysis, path optimization and parameter optimization of microchannel array precision grinding have been finished to improve processing quality and efficiency, and the deflection angle has the most obvious effects on the rectangular slot depth, micro-structured micro-grinding tool could reduce 10% surface roughness and 20% grinding force compared to original micro-grinding tool. Finally, the microchannel array has been machined with a size deviation of 2 μm and surface roughness of 0.2 μm.

Surface roughness influence on extracellular electron microbiologically influenced corrosion of C1018 carbon steel by Desulfovibrio ferrophilus IS5 biofilm

Carbon steel microbiologically influenced corrosion (MIC) by sulfate reducing bacteria (SRB) is known to occur via extracellular electron transfer (EET). A higher biofilm sessile cell count leads to more electrons being harvested for sulfate reduction by SRB in energy production. Metal surface roughness can impact the severity of MIC by SRB because of varied biofilm attachment. C1018 carbon steel coupons (1.2 cm2 top working surface) polished to 36 grit (4.06 μm roughness which is relatively rough) and 600 grit (0.13 μm) were incubated in enriched artificial seawater inoculated with highly corrosive Desulfovibrio ferrophilus IS5 at 28 ℃ for 7 d and 30 d. It was found that after 7 d of SRB incubation, 36 grit coupons had a 11% higher sessile cell count at (2.0 ± 0.17) × 108 cells/cm2, 52% higher weight loss at 22.4 ± 5.9 mg/cm2 (1.48 ± 0.39 mm/a uniform corrosion rate), and 18% higher maximum pit depth at 53 μm compared with 600 grit coupons. However, after 30 d, the differences diminished. Electrochemical tests with transient information supported the weight loss data trends. This work suggests that a rougher surface facilitates initial biofilm establishment but provides no long-term advantage for increased biofilm growth.

High-resolution metal 3D printing via digital light processing

Three-dimensional (3D) printing of complex metallic parts with a micrometer resolution can extend the application of additive manufacturing to various fields wherein the mechanical, thermal, and electrical properties of metals are essential. Digital light processing (DLP) offers high-resolution and scalable 3D printing via vat photopolymerization (VPP). We present a high-precision metal 3D printing method, namely lithography metal additive manufacturing (LMAM) that uses DLP for a photosensitive resin filled with metal powder. The printing process and sintering conditions for a stainless-steel feedstock are discussed. Highly complex and hollow structures with a spatial resolution of 35 μm and surface roughness as low as 1 <Ra < 2 μm can be printed on a decimeter scale without any support structures. The density and tensile strength of the sintered parts are 99.3 % and 93 %, respectively, of those of annealed 316 L steel. The LMAM method is suitable for manufacturing small and highly accurate devices with tailored designs in diverse areas, such as microheat exchangers, biomedical implants, and metamaterials, as well as extends metal 3D printing to chemical engineering for pharmaceutical applications.

Influence of Molybdenum Disulphide (MoS2) Nanoparticles Loading in Treated Used Palm Oil Bio-lubricant on Surface Roughness during Turning of AISI420

The environmental impact and non-biodegradability of petroleum-based lubricants has caused some researchers to shift the formulation of lubricant formulation using plant-based oil, However, food security has caused concerns in development of new bio-lubricants. In this study, treated used cooking palm oil added with Zinc Dialkyldithiophosphate and Molybdenum Disulphide nanoparticles were used as lubricant to assist the cutting of hardened martensitic stainless steel AISI420 using coated carbide tool. Surface roughness of the cut workpiece was investigated using a surface roughness tester. From the study, treated used cooking oil added with ZDDP and 0.8wt% MoS2 nanoparticles displayed the lowest average surface roughness of workpiece with Ra = 0.532µm and total roughness Rz = 4.006µm. This concluded that the new formulated bio-lubricant can successfully replace the readily available commercial cutting fluid as it produces a low surface roughness during cutting process.

Powder-Mixed Micro-Electro-Discharge Machining-Induced Surface Modification of Titanium Alloy for Antibacterial Properties

The powder-mixed electro-discharge machining (PM-EDM) technique has shown its advantages in forming surfaces and depositing elements on the machined surface. Moreover, using hydroxyapatite (HA) powder in PM-EDM enhances the biocompatibility of the implant’s surfaces. Ti-6Al-4V alloy has tremendous advantages in biocompatibility over other metallic biomaterials in bone replacement surgeries. However, the increasing demand for orthopedical implants is leading to a more significant number of implant surgeries, increasing the number of patients with failed implants. A significant portion of implant failures are due to bacterial inflammation. Despite that, there is a lack of current research investigating the antibacterial properties of Ti-6Al-4V alloys. This paper focuses on studying the performance of HA PMEDM on Ti-6Al-4V alloy and its effects on antibacterial properties. By changing the capacitance (1 nF, 10 nF and 100 nF), gap voltage (90 V, 100 V and 110 V) and HA powder concentration (0 g/L, 5 g/L and 10 g/L), machining performance metrics such as material removal rate (MRR), overcut, crater size and hardness were examined through the HA PM micro-EDM (PM-μ-EDM) technique. Furthermore, the surface roughness, contact angle, and antibacterial properties of HA PM micro-wire EDM (PM-μ-WEDM)-treated surfaces were evaluated. The antibacterial tests were conducted for Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Bacillus subtilis bacteria. The key results showed a correlation between the discharge energy and powder concentration with the antibacterial properties of the modified surfaces. The modified surfaces exhibited reduced biofilm formation under low discharge energy and a 0 g/L powder concentration, resulting in a 0.273 μm roughness. This pattern persisted with high discharge energy and a 10 g/L powder concentration, where the roughness measured 1.832 μm. Therefore, it is possible to optimize the antibacterial properties of the surface through its roughness.

High-frequency ultrasonic vibration-assisted sculpturing with a smoothed tool path for optical 3D micro-structured surfaces with sharp edges

The fabrication of complex 3D micro-structured surfaces on difficult-to-machine materials such as steel and tungsten carbide is the premise for mass production of glass components with functional surfaces by the glass moulding process. Ultrasonic vibration-assisted cutting (UVAC) is an effective method to machine 3D micro-structured surfaces on these difficult-to-machine materials. However, it is challenging and difficult for UVAC to machine microlens arrays with sharp edges, at which sudden acceleration of the z-axis slide is required to make the cutting tool follow the tool path. This could induce tool vibration and cause relative tool-work displacement, resulting in poor machining accuracy and surface finish of the machined 3D microstructure. In this paper, high-frequency ultrasonic vibration-assisted sculpturing (HFUVAS) with a smoothed tool trajectory is used to machine microlens array on steel mould for fine machining accuracy and surface quality. A comparison is made between the cutting performance of the circular microlens arrays machined by diamond turning and diamond sculpturing. The results found that relative tool-work displacement arising at sharp edge in diamond turning could be eliminated in HFUVAS with a smoothed tool path, demonstrating the effectiveness of a smoothed tool path in reducing relative tool-workpiece displacement in the fabrication of 3D micro-structured surfaces. Furthermore, a quadrilateral microlens array and hexagonal microlens array are also fabricated in order to extend the applications of HFUVAS, with a form error within 1 μm and surface roughness with an arithmetical mean height Sa of below 10 nm achieved.

Fretting fatigue life improvement of nickel-based superalloy GH4169 dovetail slots by deflecting abrasive waterjet peening process

The proposed deflecting abrasive waterjet peening (DAWJP) process can be used for surface strengthening of metallic parts with confined space features, which has great potential to improve the surface integrity and fretting fatigue (FF) life of dovetail slots in turbine discs. In this paper, the nickel-based superalloy GH4169 dovetail slot is strengthened by DAWJP and shot peening (SP), and the effects of DAWJP and SP on surface integrity and FF performance of the dovetail slot are investigated. First, the DAWJP with three different processes (water pressure of 205 MPa, traverse speed of 5 mm/s, standoff distance of 2 mm, and path interval of 0.05, 0.1, and 0.15 mm) and the SP with one process (peening intensity of 0.25 mmA with coverage of 100%) were conducted on the contour surface of the dovetail slot. The surface integrity of the dovetail slot before and after the DAWJP and SP treatment was investigated, including microstructure, surface roughness and microscopic morphology, microhardness, and residual stress. Results showed that the dovetail slot treated by the DAWJP with different path intervals formed a plastic deformation layer with a thickness of 22–43 μm and surface roughness Ra and Sa of 0.391–0.501 μm and 0.763–0.907 μm. The surface microhardness and CRS of the DAWJP-treated dovetail slot were approximately 541–591 HV and 1005–1169 MPa, 16%–27% and 178%–224% times higher than the as-received dovetail slot. The SP-treated dovetail slot produced relatively large surface roughness, slight plastic deformation, and low microhardness and CRS compared with the DAWJP-treated dovetail slot. Finally, FF tests were carried out to study the FF behavior of the dovetail slot before and after DAWJP and SP treatment. The FF lives of the dovetail slot treated by DAWJP were 4.82 and 3.91 times that of the as-received dovetail slot at room temperature and a high temperature of 650 °C. In contrast, the FF lives of the SP-treated dovetail slot were 2.96 and 1.96 times that of the as-received specimen at room temperature and a high temperature of 650 °C, which verified that DAWJP has a more significant effect on improving the FF life of dovetail slots than the SP treatment used for comparison. The FF fracture and fretting contact surface and its cross-sectional microstructure were examined, and the results showed that the extreme grain refinement, large CRS, and high work-hardening induced by DAWJP could be the key to greatly improving the FF life of dovetail slots. This work takes the lead in the surface treatment of dovetail slots through the proposed DAWJP process, which provides a feasible reference plan for effectively and economically improving the FF resistance of dovetail slots in turbine discs.

Submerged deflecting abrasive waterjet peening for improving the surface integrity and solid particle erosion resistance of Ti-6Al-4V alloy

Waterjet peening is a promising new surface treatment technology, which is increasingly used to improve a metal's surface integrity and mechanical properties. In this study, the surface integrity and solid particle erosion (SPE) resistance of Ti-6Al-4V alloy treated with submerged deflecting abrasive waterjet peening (SDA-WJP) at different standoff distances (D = 3, 6, and 9 mm) were investigated. First, the surface integrity of specimens before and after SDA-WJP treatment was compared, including microstructure, surface roughness, micromorphology, microhardness, and compressive residual stress (CRS). The test results showed that the SDA-WJP-treated specimens formed refined grain deformation layers of 8–24 μm and minimum roughness of Ra = 0.28 μm and Sa = 0.55 μm. The thicknesses of the refined grain hardening layer and CRS field were 140–180 and 120–200 μm, respectively. Finally, the SPE behavior and mechanism of the samples before and after SDA-WJP treatment were studied in the SPE test. The highest increase in SPE resistance was 51 % under different SDA-WJP processes. The microscopic morphology of the eroded surface was observed by scanning electron microscopy. The shallow embedding depth of the particles on the eroded surface after SDA-WJP treatment led to difficult platelet formation for removal. The introduced refined grain hardening layer and CRS field were critical in preventing micro-crack initiation and propagation. This work optimizes the SDA-WJP process parameters for improving the surface integrity and SPE resistance of Ti-6Al-4V alloy, thus providing a reference for the application of SDA-WJP for the improvement of the SPE resistance of aero-engine blades.

Fabrication of curved aspheric compound eye microlens array with high surface quality by precision glass molding

The curved compound eye microlens array (CEMLA) glass optical element is widely used in optoelectronic detectors because it affords a high image quality and a large field of view. However, fabrication of high-precision glass optical elements with a small cell size and many arrays on hard and brittle glass materials is challenging. Here, we report a fabrication method to address molding challenges for high quality CEMLA glass optical elements at molding temperatures up to 500 °C. First, an Ni-P with good turning performance and low adhesion to glass is chosen as the plating material, the CuNi is selected as the mold substrate for their close CTEs. To prevent the diffusion of P to the surface of optical elements and to improve the hardness and wear resistance of mold, a Ti-Ta-C coating is deposited on the Ni-P mold. By single-point diamond turning on the Ni-P surface using a fast tool servo, an aspherical CEMLA mold with a form accuracy PV less than 0.4 μm and surface roughness Sa less than 4 nm was machined. Finally, based on the creep testing of microdeformation compression, an accurate viscoelastic constitutive model of glass was established. Optimization of the molding process and accurate prediction of molding profile deviation were simulated. The aspheric CEMLA glass optical element with a form accuracy PV less than 0.5 μm and surface roughness Sa less than 4.5 nm was obtained by precision glass molding (PGM).

Influence of the Duty Cycle of Pulse Electrodeposition-Coated Ni-Al2O3 Nanocomposites on Surface Roughness Properties

In this study, the viability of duty cycle variation was explored as a potential method to improve the mechanical and surface roughness properties of Ni-Al2O3 nanocoatings through pulse electrodeposition. The areal and surface roughness properties of nanocomposite pulse electrodeposition-coated materials with varying duty cycles from 20% to 100% was studied with the analysis of bearing area curves and power spectral densities. Results demonstrate that with decrease in duty cycle, there was an enhancement in aerial roughness properties from 0.348 to 0.195 µm and surface roughness properties from 0.779 to 0.245 µm. The change in surface roughness was due to grain size variation, resulting from the varying time intervals during pulse coatings. This increase in grain size with the change in duty cycle was confirmed with the scanning electron microscope. In addition, an increase in grain size from 0.32 to 0.92 µm with an increase in duty cycle resulted in a decrease in nanohardness from 4.21 to 3.07 GPa. This work will provide a novel method for obtaining Ni-Al2O3 nanocomposite coatings with improved surface roughness and hardness properties for wider industrial applications.

Study on picosecond laser stealth dicing of 4H-SiC along [[formula omitted]] and [[formula omitted]] crystal orientations on Si-face and C-face

Stealth dicing of semi-insulating 4H-SiC along [112¯0] and [11¯00] crystal orientations on Si-face and C-face was conducted by using infrared picosecond laser in combination with three-point bending split. It was demonstrated that the laser ablation points inside 4H-SiC samples, the critical fracture load, and the dicing quality of 4H-SiC samples were closely related to the crystal orientation. The critical fracture load of 4H-SiC along [112¯0] orientation is smaller than that along [11¯00] orientation. The longitudinal lengths of the laser ablation points increase with the increase of laser incident distance. For the same laser-modified layer, as laser was incident from C-face and processed along [112¯0] orientation, the laser ablation points have larger longitudinal length. The reasons for the impact of crystal orientation on laser-modified points were analyzed. The fractured 4H-SiC samples have chipping width less than 3 μm and section roughness less than 500 nm. Moreover, the dicing quality along [112¯0] orientation is better than that along [11¯00] orientation. This research can provide technical support for precision dicing of SiC wafers in semiconductor industry.

Enhancement of heat transfer on micro- and macro- structural surfaces in close-loop R410A flashing spray cooling system for heat dissipation of high-power electronics

High effective spray cooling system is urgently required for the thermal management of high-power electronics in small areas. These electronic devices need to be cooled at functional operating temperature, and it is particularly lacking in current spray cooling studies. For this purpose, a hybrid structural surface that integrates micro- roughness and macro- structure is investigated in close-loop R410A flash spray cooling system. The heat transfer performance is tremendously enhanced as the increase of roughness on flat surface until it reaches the value of 3.5 μm. Meanwhile, a novel tetrahedral fin surface is proposed and compared with modified surfaces including flat, wavy, square, and pyramid fins. It performs high heat flux of 411.2 W cm−2, a 101.5 % enhancement over the flat surface. What’s more, the hybrid structure with 3.5 μm roughness can further improve the maximum critical heat flux and heat transfer coefficient by up to 424 W cm−2 and 814 kW K−1 m−2, respectively, while keeping the surface temperature below 50 °C. Besides, correlations and energy efficiency are studied to explore the performance of structural surfaces. These findings in a wider range of roughness and macrostructure will provide insights to guide the surface modification in flash spray cooling.

The Technological Factors and Operating Conditions Influence on the Molybdenum Disulfide Coatings Tribological Properties

Molybdenum disulfide is a widely used solid lubricant operates successfully under extreme conditions such as vacuum, high or low temperatures, high loads etc. Magnetron sputtering is one of the most common method of application MoS2 coatings. It allows one to apply thin antifrictional films with high rate of purity on different substrates. The surface before application is usually prepared by abrasive processing. The aim of the work is to evaluate the magnetron deposition modes, substrate surface preparation, substrate roughness on the molybdenum disulfide coatings tribological properties. For the purpose mentioned a linearly reciprocating Ball-on-Flat (ASTM G133) Sliding Wear tests in vacuum (pressure less than 10-4 mbar) and high temperature (250 ¬¬¬0C) were conducted. The two different materials as a coating substrate was used (stainless steel and brass). The substrate surface was sandblasted. The coating surfaces structure after wear and chemical composition have been studied. The friction coefficient in vacuum at 250 °C was about 0.02–0.05. The least value was observed for the AISI 316L steel substrate treated by sandpaper and Ra 0.10 µm roughness coatings. The negative bias voltage (–20 V) during magnetron deposition leads to 16–42% lower coefficient of friction. Oxygen decreases the anti-friction properties.

Investigation on multi-physical field simulations of blade ECM using vertical flow

Electrochemical machining (ECM), an advanced manufacturing technology, is widely used in aero-engine blades machining. In traditional ECM, the electrolyte flows through the inter-electrode gap (IEG), generating hydrogen bubbles and heat, which affect the conductance and thus influence the machining quality. This paper focuses on the effect of bubble movement on the flow field and the machining quality of ECM. A novel vertical flow mode of electrolyte is proposed according to the bubbles dynamics analysis. Multi-physical fields simulations of blade ECM using vertical and horizontal flows were carried out. With an initial gas void fraction, flow rate, and temperature at the inlet of 0, 19.7 m/s, and 302.65 K, respectively, in both flow modes, the vertical flow reduces the gas void fraction, flow rate, and temperature at the outlet by 2.4%, 0.4 m/s, and 0.6 K, and increases the conductance by 0.47 S/m. Thus, the vertical flow of the electrolyte is beneficial in reducing the gas void fraction and controlling the temperature rise, while enhancing the conductance. Then, the corresponding experiments using a vertical flow were carried out. The maximum machining deviation ranges from 3.4 to 75.6 μm and surface roughness Ra < 0.35 μm. The machining quality is high and the variation observed in the experiments is consistent with the simulation results, the validity and correctness of the simulations are verified. Thus, the vertical flow mode proposed in this paper is appropriate, can be used for other complex structures in ECM.

Estimation of Surface Roughness on Milled Surface Using Capacitance Sensor Based Micro Gantry System through Single-Shot Approach.

The profile generation is highly complex for roughness measurement using a capacitive sensor because of the small peak-to-peak width of the machined surface and the close proximity of the sensor setting with the machining setup which has the chance of damaging the sensor. Considering these shortcomings, a higher sensor sensing diameter with an appropriate resolution has been selected for a single-shot approach. An automated micro gantry XYZ system is integrated with a capacitive sensor to precisely target, move, and measure the roughness. For investigation, a vertical milled surface with a wide roughness range has been prepared. A Stylus profilometer has been used to measure the roughness (Ra) of the specimens for comparison. An experiment has been conducted on the above system with a 5.6 mm capacitance sensor, and an estimation model using regression has been obtained using sensor data to estimate Ra. In conclusion, the single-shot approach with a 5.6 mm sensing diameter sensor, the proposed micro gantry system, and the estimation model performs better in instantaneous noncontact measurement in the range of 0.3 µm to 2.9 µm roughness estimation. The influence of tilt and waviness has also been discussed using FEA analysis.

Electrochemical Micromachining of Linear Micropattern on Stainless Steel Surface

Maskless electrochemical micromachining process with SU-8 2150 masked tool has been introduced containing microstructures with higherprofile accuracy that are generated on SS-304. In this research work, to make maskless EMM method with more cost-effective, substantial adaptations are provided to this technique and an advanced version of EMM process is applied for microtexturing. In this modified technique, a special microtextured cell unit including (micromachining cell, electrical connection, and electrolyte flow scheme) is assembled by the mechanical force and perpendicular cross flow system has been developed inside the cell. Experimentation is conducted to explore the machining influence of the advanced maskless EMM process for fabricating linear micropattern. The machining outcomes of voltage, frequency, and duty ratio on MRR, dimensional accuracy, textured depth, and surface roughness are investigated during microtexturing. The investigational research reveals that this advanced maskless EMM technique can generate highly identical micropatterns having MRR of 2.2 mg/min, width overcut of 19.76μm, textured depth of 14.4μm and surface roughness of 0.0307μm.

Influence of surface morphology parameters of steel on tribological properties between glass‐fiber‐reinforced polytetrafluoroethylene composites and steel under dry‐friction and oil‐lubrication conditions

AbstractPolytetrafluoroethylene (PTFE) composites are commonly used engineering materials owing to their good tribological and mechanical properties. In this study, a friction pair was formed by a glass‐fiber‐reinforced PTFE composite and a chromium‐plated nickel‐based stainless steel plate (18Cr2Ni4WA). Under dry‐friction and oil‐lubrication conditions, friction and wear tests were carried out on the metal plate surface in two roughness ranges and three surface‐texture directions. The friction coefficient, wear rate, width and depth of the wear trace, wear morphology, and surface composition were analyzed. The results showed that the 90° texture direction of the steel plate with respect to the moving direction under oil lubrication and the 0° texture direction under dry friction were the texture directions with the best tribological performance. The friction and wear properties of the PTFE composite under dry friction were better than those under oil lubrication. The 0.3–0.5 μm roughness range of the steel plate was the best roughness range for the tribological properties of the matching pairs.