Workpiece Roughness Research Articles

Effect of Parameters of Chemical Mechanical Polishing (CMP) for Improving Surface Roughness for Semiconductor Material Kind Silicon

Chemical Mechanical Polishing (CMP) is the polishing process where the top surface of a wafer is smoothed using a slurry containing abrasive grit as well as reactive chemical agents. The polishing process is partly mechanical and partly chemical. The mechanical element's main advantage is that it is achieved without great effort to manufacture and supplies good-quality general mechanical and electrical properties. In the current study, the invention reckons on the chemical and mechanical properties of the composition particles (abrasive slurry) utilized to polish silicon surfaces traveling through chemical-mechanical polishing (CMP). MINITAB 17 software was used to estimate the influence of the (CMP) input variables on the surface roughness (Ra) of the silicon workpiece. Other process input variables were disk speed (rpm), the dose of abrasive, the grain size of the abrasive, and the type of slurry. In order to get the best response surface roughness, the current findings show that the constant coefficient of determination (R2) is 95.80%. Furthermore, the effects of disk speed (X1), abrasive dose (X2), abrasive grain size (X3), and type of slurry (X4) on achieving a superior surface roughness finish were 21.05%, 4.34%, 50.00%, and 24.59%, respectively.

Research on Cutting Layer Characteristics of Superalloy under High-Pressure Cooling.

Superalloys are widely used in the aerospace field and are a typical difficult-to-cut material. When the PCBN tool is used to cut superalloys, there will be problems such as a large cutting force, a high cutting temperature, and gradual tool wear. High-pressure cooling technology can effectively solve these problems. Therefore, this paper carried out an experimental study of a PCBN tool cutting superalloys under high-pressure cooling and analyzed the influence of high-pressure coolant on the characteristics of the cutting layer. The results show that the main cutting force can be reduced by 19~45% and 11~39% when cutting superalloys under high-pressure cooling compared with dry cutting and atmospheric pressure cutting, respectively, in the range of test parameters. The surface roughness of the machined workpiece is less affected by the high-pressure coolant, but the high-pressure coolant can help reduce the surface residual stress. The high-pressure coolant can effectively improve the chip's breaking ability. In order to ensure the service life of PCBN tools, when cutting superalloys under high-pressure cooling the coolant pressure should not be too high, and 50 bar is more appropriate. This provides a certain technical basis for the efficient cutting of superalloys under high-pressure cooling conditions.

An Experimental Study of the Effects of Coolant Fluid on Surface Roughness in Turning Operation for Brass Alloy

The effect of different cutting fluids on surface roughness of brass alloy workpiece during turning operation was carried out in this research. This was performed with different cutting speed, while other cutting parameters had been regarded as constants(feeding rate , and depth of cut). Surface roughness of machined parts that will be tested by electronic surface roughness tester .The results show that the standard coolant gives the best values of surface roughness for fixed cutting speed ,followed by sun flower oil that has approximately the same effect, while the air stream as a coolant gave unsatisfied results for the evaluation of surface roughness.
 In the other hand the best values of surface roughness were recorded for maximum cutting speed with all other types of cutting fluids.

Plasma Polishing as a New Polishing Option to Reduce the Surface Roughness of Porous Titanium Alloy for 3D Printing.

Porous titanium alloy implants with simulated trabecular bone fabricated by 3D printing technology have broad prospects. However, due to the fact that some powder adheres to the surface of the workpiece during the manufacturing process, the surface roughness in direct printing pieces is relatively high. At the same time, since the internal pores of the porous structure cannot be polished by conventional mechanical polishing, an alternative method needs to be found. As a surface technology, plasma polishing technology is especially suitable for parts with complex shapes that are difficult to polish mechanically. It can effectively remove particles and fine splash residues attached to the surface of 3D printed porous titanium alloy workpieces. Therefore, it can reduce surface roughness. Firstly, titanium alloy powder is used to print the porous structure of the simulated trabecular bone with a metal 3D printer. After printing, heat treatment, removal of the supporting structure, and ultrasonic cleaning is carried out. Then, plasma polishing is performed, consisting of adding a polishing electrolyte with the pH set to 5.7, preheating the machine to 101.6 °C, fixing the workpiece on the polishing fixture, and setting the voltage (313 V), current (59 A), and polishing time (3 min). After polishing, the surface of the porous titanium alloy workpiece is analyzed by a confocal microscope, and the surface roughness is measured. Scanning electron microscopy is used to characterize the surface condition of porous titanium. The results show that the surface roughness of the whole porous titanium alloy workpiece changed from Ra (average roughness) = 126.9 µm to Ra = 56.28 µm, and the surface roughness of the trabecular structure changed from Ra = 42.61 µm to Ra = 26.25 µm. Meanwhile, semi-molten powders and ablative oxide layers are removed, and surface quality is improved.

Effects of cryogenic treatment on the performance of coated tungsten carbide inserts during milling of EN24 steel

Cryogenic treatment is one of the innovative techniques to improve the performance of cutting tools. The present study investigated the effects of cryogenic treatment on the performance of cutting tools, while machining (CNC milling) EN24 steel. The TiCN-coated tungsten carbide inserts (APKT09) were procured and exposed to shallow cryogenic treatment at −80 °C for 6 h and deep cryogenic treatment at −196 °C for 24 h independently. The experiments were designed using Taguchi’s L9 orthogonal array. Milling tests were performed by considering three cutting speeds (1900, 2200, and 2500 rpm), three feed rates (350, 440, and 530 mm/min), and three depths of cut (0.40, 0.65, and 0.90 mm) under dry cutting conditions. The machining performance of cryogenically treated and untreated inserts was evaluated in regard to the flank wear of the inserts and the surface roughness of the machined workpiece. Cryogenically treated inserts exhibited reduced flank wear and surface roughness than untreated inserts. The best flank wear and surface roughness performance were attained with the deep cryogenically treated inserts. Moreover, an improvement in the microhardness of the cryo-treated inserts was observed.

Surface Roughness of Workpiece and Temperature Effects of Cutting Fluids on High-Speed Steel Tool

The major needs in machining are high material removal rate, good work surface finish and low tool wear. However, machining process often encounter tools wear problem which leads to increased product cost and poor quality. The aim of the study is to determine the effects of surface roughness and temperature of the cutting fluids on high-speed steel tool. High-speed steel (HSS) cutting tool was used on Colchester triumph space bed Centre lathe to work on a mild steel using cutting fluid such as soluble oil, liquid soap, and engine oil. The feed rate, spindle speed and depth of cut of the mild steel work piece were kept constant. The surface coarseness and temperature of the machine was examined with the three types of cutting fluid used. This result indicated that among the three cutting fluids used in the study, the liquid soap has the best temperature reduction on the chips (38.02℃), tool tip (40.73 oC), and the workpiece (40.03 oC); while soluble oil cutting fluid had a good surface finished of 0.8 mm, thus makes it more desirable cutting fluid in machining operation.

Investigation into the laser polishing of an austenitic stainless steel

Gas shielding is critical for improving the quality of laser polishing. The processing effects of laser polishing under the chamber and nozzle gas shielding were compared and analyzed. The influence of the volume flow rate on the surface roughness of the polished workpiece was analyzed, determining the optimal volume flow rate (Q = 5 L/min). At the optimum volume flow rate, the effects of laser power and scanning speed on surface roughness were explored in further research on nozzle gas shielding laser polishing with wider application prospects. A shielding gas jet model for nozzle gas shielding laser polishing was established and verified. The influence mechanism of the shielding gas jet on the polished surface topography was explored using the established shielding gas jet model and laser polishing model, revealing the formation mechanism of surface ripples on the polished surface: the shielding gas jet acts as a perturbation of the molten pool, causing the Marangoni instability of the molten pool when the Marangoni number exceeds the critical Marangoni number.

Effect of nanoparticles mixing-ratio of Al2O3-MWCNT hybrid nano-cutting fluid during MQL turning

ABSTRACT Recent research has focused on replacing traditional cutting fluids with nano-cutting fluids to enhance machining performance. Also, hybrid nano-cutting fluid composed of two or more types of nano-particles has gained popularity. The aim of this study is to investigate the effect of the mixing ratio of Al2O3 (Alumina) and MWCNT (multiwall carbon nanotubes) nanoparticles blended in vegetable oil during the turning of stainless steel SS-304 with minimum quantity lubrication (MQL) cutting conditions. Two hybrid nano-cutting fluids with 1.5% weight concentration have been prepared using Al2O3 and MWCNT nanoparticles in the ratio of 80:20 and 60:40. The performance of hybrid nano-cutting fluids containing nanoparticles of both Al2O3 and MWCNT simultaneously has been compared with mono nano-cutting fluid containing only Al2O3 nanoparticles. Results show that use of hybrid nano-cutting fluid containing 20% and 40% MWCNT resulted in improvement in surface roughness of workpiece by 13.6% and 6.86%, respectively, over mono nano-cutting fluid.

Minimum roughness value in PMEDM with low-frequency vibration applied to workpiece

In powder-mixed electrical discharge machining (PMEDM), the application of low-frequency vibrations to a workpiece is considered beneficial to the machining quality. This study evaluates the average surface roughness (Ra) of SKD61 steel workpieces subjected to low-frequency vibrations during PMEDM using a Cu electrode and titanium powder. Specifically, Taguchi’s L25 experimental design method is used to evaluate the influence of the following process parameters: current, pulse-on time, concentration, push pressure, frequency, and amplitude. The analysis of variance technique is used to determine the minimum Ra (Ra[Formula: see text]) value. The results show that Ra is most and least strongly influenced by [Formula: see text] and [Formula: see text], respectively. Further, Ra[Formula: see text] is found to be 1.03 [Formula: see text]m.

An overview of material removal processes and its importance

Good surface finishing, quality, and maximizing metal removal are characteristics feature of machining operation. The process variables affect the product’s surface roughness and rate of metal removal. Proper management of the process variables makes it easier to lower machining costs and enhance product quality. In order to get the best product, extensive research has been done previously to optimize the procedure specifications in any machining process. This paper studies how important the material removal process is, its benefits, and its relevancy in the manufacturing industries. The most recent turning process research uses the Response Surface Methodology (RMS). Process variables including feed, cutting speed, and depth of cut work well. In most circumstances, a technical need for mechanical products, the surface profile, and the roughness of a machined workpiece are two of the most significant product quality features. The necessary surface quality must be obtained for a part to function as intended. Finding a simple solution and a completely reliable approach is crucial due to the surface quality mechanism’s process dependence and the various uncontrollable elements that affect relevant phenomena.

Titanium alloys surface integrity of belt grinding considering different machining trajectory direction

The interplay of abrasive grains and materials complicates the grinding of titanium alloys by abrasive belts. Notably, the influence relationship of surface generation for complex curved workpieces such as hollow blades needs to be clarified, making precise control of the surface integrity of complex surfaces difficult in abrasive belt grinding applications. This paper thus proposes a trajectory planning method based on the direction of interaction between grinding grains and materials to reveal its influence law on the surface integrity of complex curved surfaces of titanium alloy with unevenly distributed machining allowances. First, a machining trajectory with different angles between the grinding direction and feed direction is proposed. In order to determine the corresponding experimental scheme for titanium alloy hollow blades. Experimental results are used to analyze the influence of different grinding trajectory directions on the surface roughness, residual stress, surface topography, and accuracy of the contours. The results show that different grinding trajectory directions significantly affect the workpiece’s surface integrity. By varying the grinding trajectory direction, it is possible to reduce the surface roughness of titanium alloy workpieces by approximately 40%, increase the surface residual compressive stress by approximately 50%, provide a finer workpiece surface and improve the consistency of the surface texture. This work is expected to guide the efficient and high-quality machining of complex curved parts such as titanium alloy hollow blades.

Evaluation of Surface Roughness, Tool Wear and Chip Morphology during Machining of Nickel-Based Alloy under Sustainable Hybrid Nanofluid-MQL Strategy

Nickel-based super alloys exhibit high strength, oxidation and corrosion resistance; however, the machining of these alloys is a challenge that can be overcome with effective cooling/lubrication techniques. The use of a minimum quantity lubrication (MQL) technique is limited to lower cutting parameters due to the tremendous heat produced during the machining of Inconel 718. Sustainable and eco-friendly machining of Inconel 718 can be attained using MQL and lubricants based on nanofluids because of their improved heat transfer capabilities. For that purpose, the performance of hybrid nanofluid-MQL is examined. In this novel study, graphene and hexagonal boron nitride (hBN) nanoparticles are reinforced with palm oil and delivered to the machining interface using an MQL setup. The machining experiments are performed under the conditions of dry, wet, MQL and MQL with graphene/hBN deposited in palm oil. The machining performance under selected cutting conditions is assessed by analyzing the surface roughness, tool wear, chip morphology and surface quality of the machined workpiece. A comparison of results showcased the effectiveness of hybrid nanofluid-MQL with improvement in surface finish, reduction in tool wear and favorable chip forms concerning all other machining conditions.

1DCNN-BiGRU network for surface roughness level detection

Surface roughness was regarded as an essential indicator of the quality of machining. In machining demands, it was often necessary that the surface roughness of the workpiece lies in a specific range.For this reason , it was significant to detect the surface roughness level of the workpiece. For the traditional roughness detection methods with high manual involvement and unable to achieve automation, this paper proposed a new artificial intelligence detection approach. The approach consisted of a 1-Dimensional Convolutional Neural Network (1DCNN) and a Bi-directional Gated Recurrent Unit Network(BiGRU), called the 1DCNN-BiGRU model. 1DCNN-BiGRU accomplished the detection of roughness levels by classifying surface images directly, without extracting specific roughness features. First, 1DCNN was applied to automate the extraction of roughness-related features along the texture direction of the product surface image. Subsequently, the feature sequences extracted by 1DCNN were fed into BiGRU to learn the overall dependence of the roughness on the sequences. Experiments were performed on a 45steel workpiece roughness image dataset. The 1DCNN-BiGRU model gave 90.60% and 88.06% detection performance on the training and test sets, respectively.

The Influence of Surface Texturing of Ceramic and Superhard Cutting Tools on the Machining Process-A Review.

Machining is an indispensable manufacturing process for a wide range of engineering materials, such as metals, ceramics, and composite materials, in which the tool wear is a serious problem, which affects not only the costs and productivity but also the quality of the machined components. Thus, the modification of the cutting tool surface by application of textures on their surfaces is proposed as a very promising method for improving tool life. Surface texturing is a relatively new surface engineering technology, where microscale or nanoscale surface textures are generated on the cutting tool through a variety of techniques in order to improve tribological properties of cutting tool surfaces by reducing the coefficient of friction and increasing wear resistance. In this paper, the studies carried out to date on the texturing of ceramic and superhard cutting tools have been reviewed. Furthermore, the most common methods for creating textures on the surfaces of different materials have been summarized. Moreover, the parameters that are generally used in surface texturing, which should be indicated in all future studies of textured cutting tools in order to have a better understanding of its effects in the cutting process, are described. In addition, this paper proposes a way in which to classify the texture surfaces used in the cutting tools according to their geometric parameters. This paper highlights the effect of ceramic and superhard textured cutting tools in improving the machining performance of difficult-to-cut materials, such as coefficient of friction, tool wear, cutting forces, cutting temperature, and machined workpiece roughness. Finally, a conclusion of the analyzed papers is given.

Analisis Pengaruh Kecepatan Putaran Spindel Terhadap Kekasaran Permukaan Benda Kerja Pada Proses Pengerjaan Mesin Bubut

The purpose of this research was to obtain a result from the effect of the influence of spindle rotation speed on the roughness of the workpiece using rugotest by knowing the different roughness treatments of each rpm specimen. This research uses an experimental method, workpieces with the type of steel material ST.37 made 10 specimens in the form of 2 workpieces. Each workpiece contains 5 specimens to be analyzed using the rugotest tool at different variations of spindle rotation speed. Variations of spindle rotation speed are 693 rpm, 501 rpm, 252 rpm, 125 rpm, and 63 rpm. Turned using the same tool and the same feeding speed on one variable. After the workpiece is turned it is then analyzed to get the roughness value of the workpiece. Data analysis using rugotest by knowing the standard value of roughness on the rugotest. This study obtains data results that show the faster the spindle rotation on the lathe, the lower the workpiece roughness value on the rugotest.

Thermal Modelling and Experimental Validation in the Perspective of Tool Steel Laser Polishing

Laser polishing (LP) is a process that allows a significant reduction of the surface roughness of a metal workpiece via re-melting a shallow layer of material. However, the practical use of LP is limited due to the difficulty of satisfying the high surface polishing quality for industries such as jewelry. Hence, this study presents a thermal model based on the Chernoff formula for fixed and moving LP processes. The model was validated via a sensitivity analysis of the coefficient of absorption of the solid and liquid phase and through comparing the results with the corresponding experimental observations of the melt pools produced. In this investigation, a continuous wave, high power diode laser (980 nm wavelength, Ø 0.9 mm spot size with a flat top distribution) was coupled to a fixed focusing head. The material was a hardened tool steel (X38CrMVo5-1 steel-1.2343) with an initial surface state obtained by electrical discharge machining (EDM) of CH30 on the Charmilles scale for EDM, which corresponds to a roughness Ra of 3.15 µm. The results show that the model is able to represent the thermal behavior of the tool steel during LP. The best results are obtained with two constant coefficients, one for the solid based on the measurement at room temperature (as = 35%) and one for the liquid fixed so that the model fits the experiment data (al = 25%).

Study of grinding and polishing tools in automated processing of curved stone

The grinding and polishing of curved stone involve many steps, limiting the process's efficiency. This study proposes a one-step grinding and polishing process to simplify the process and achieve efficient machining. It is achieved by developing the grinding and polishing tools and realizing the entire process on the robotic processing platform, and the tool design is based on the surface roughness of the machined workpiece. The grinding tool is made by selecting the appropriate glue to achieve the connection from carving to polishing. Similarly, the polishing tool is made by selecting the appropriate gel compound system to achieve a high glossiness curved stone surface. The results show that the grinding tool made of epoxy resin YT-CC301 can reduce the curved stone's roughness from 16.281 µm to below 400 nm, and the connection from carving to polishing can be realized by one step. The polishing tool made of sodium alginate and carboxylated chitosan gel compound system or sodium alginate and sodium carboxymethyl cellulose gel compound system can polish the surface of the ground curved stone to the roughness of less than 15 nm, and the surface glossiness can reach more than 120. Therefore, a single step of grinding and polishing of curved stone is achieved.

The Influence of Diamond Burnishing Process Parameters on Surface Roughness of Low-Alloyed Aluminium Workpieces

This study describes the determination and optimization of burnishing process parameters and their effects on surface roughness of EN AW-2011 aluminium alloy workpieces. The process has a low environmental load and the chip-free burnishing process improves the integrity of the machined surface, but to achieve this, the different burnishing parameters, for example, burnishing force, feed rate, speed and number of passes, must be properly defined according to the material of the workpiece. In our research, a full factorial experimental design method is used to plan and carry out the experiments and to determine the most appropriate parameter range for this material quality.

An Image-Based Data-Driven Model for Texture Inspection of Ground Workpieces.

Nowadays, the grinding process is mostly automatic, yet post-grinding quality inspection is mostly carried out manually. Although the conventional inspection technique may have cumbersome setup and tuning processes, the data-driven model, with its vision-based dataset, provides an opportunity to automate the inspection process. In this study, a convolutional neural network technique with transfer learning is proposed for three kinds of inspections based on 750–1000 surface raw images of the ground workpieces in each task: classifying the grit number of the abrasive belt that grinds the workpiece, estimating the surface roughness of the ground workpiece, and classifying the degree of wear of the abrasive belts. The results show that a deep convolutional neural network can recognize the texture on the abrasive surface images and that the classification model can achieve an accuracy of 0.9 or higher. In addition, the external coaxial white light was the most suitable light source among the three tested light sources: the external coaxial white light, the high-angle ring light, and the external coaxial red light. Finally, the model that classifies the degree of wear of the abrasive belts can also be utilized as the abrasive belt life estimator.

Enhancing the wear performance of WC-6Co tool by pulsed magnetic field in Ti-6Al-4V machining

To prolong the service life of titanium alloy machining tools, pulsed magnetic field treatment technology is used to enhance the wear performance of tools. The cutting force, rake wear, surface roughness, cutting chips and thermal conductivity in titanium alloy cutting process were investigated to reveal the effect of magnetic field treatment on titanium alloy machining tools. The results show that magnetic field treatment can prolong the service life of titanium alloy cutting tools, especially in wet conditions, the flank wear of the treated tool is reduced 59.8 % on average, the cutting force of the treated tool is reduced by 30 %, and the surface roughness of machined workpiece is reduced by 10.5 %. The reason is that the thermal conductivity of the tool after pulse magnetic field treatment increases by 6.5 %, which reduces the temperature of the cutting friction area. Meanwhile, a uniform titanium film is formed on the rake face of the treated tool to obtain better lubrication. Therefore, it is positive to enhance the wear performance of titanium alloy machining tools by pulsed magnetic field, which is of great significance to the development of titanium alloy machining.