Surface roughness measurement using an optical system

In this study, model equations to predict average surface roughness value of abrasive water jet cut aluminium 6061 alloy are developed. Model equations are developed considering water jet pressure, abrasive flow rate and traverse speed of the jet. Model equations help in knowing average surface roughness value on the cutting and deformation wear regions. 27 abrasive water jet cutting experiments are conducted on trapezoidal shaped aluminium 6061 block. Depth of penetration values are found for all experimental cutting conditions. Average surface roughness values are found by non-contact surface roughness tester. Surface roughness testing is carried out along the length of depth of penetration. Low and high average surface roughness values are noticed on the cutting and deformation wear regions respectively. Smooth surface finish and rough surface finish with striations are observed on the cutting and deformation wear regions respectively.

Varying cutting angles are applied to understand the relationship between cutting angles and machining result characteristics, such as surface roughness (Ra). Surface roughness as a dependent variable is influenced by machining parameters, namely depth of feed. Cutting angle, cutting speed and feed speed as independent variables. The aim of the research activity is to analyze the effect of variations in the cutting angle of carbide tools and identify the optimum cutting angle on the surface quality of the axle rail shaft from AISI 4337 steel processed using the dry turning method. The research was carried out experimentally, which had 9 specimens as test material to obtain surface roughness values ​​with variations in cutting angles using a CNC lathe without cutting fluid and a surface test tool. Test data is provided with machine spindle rotation speeds, namely 1200 rpm, 1400 rpm and 1600 rpm. Variations in cutting angles of 25o, 55o, 85o and feeds of 0.1 mm/r, 0.15 mm/r, 0.2 mm/r and a constant cutting depth of 1 mm are used for the dry turning process which is commonly used in industry to reduce the environmental impact . The average surface roughness (Ra-avg) values ​​of 3.05 μm, 2.35 μm, 1.64 μm obtained as a function of cutting angle are part of the optimum cutting conditions on HP9. From the analysis, it was found that the most optimum cutting angle (Kr) was an angle of 85o with an average surface roughness value (Ra-avg) of 1.64 μm as shown in figure 4.3. The results show that larger cutting angles tend to produce surfaces with lower roughness, while smaller angles can increase the tool wear rate. Factors such as cutting speed, depth of cut, and feed rate also influence the results significantly. This research provides important insights for the optimization of machining processes in industrial applications.

In this study, three different detox drinks were examined for their effects on the surface roughness, colour change (∆E00), and transparency parameters (∆TP00) of universal resin composites. One hundred twenty samples were prepared, thirty each of universal resin composites (Omnichroma, OptiShade, Filtek Ultimate Universal, and Essentia Universal). Initial values were measured. The samples were randomly divided into three subgroups and exposed to the detox drinks. Measurements were repeated after 7, 14, and 28 days of exposure to detox drinks. The highest average surface roughness values in detox drinks were obtained with Essentia Universal. It was found that average surface roughness values increased over time, and there was a significant difference between the average surface roughness values obtained during the measurement periods (p < 0.05). In all detox drinks, the lowest ∆E00 values were obtained on days 7 and 14 with OM, while the highest ∆E00 values were obtained on day 28. There was a significant difference in the ∆E00 values of the universal resin composites tested at each time point (p < 0.05). The highest ∆TP00 values were obtained from OM in all periods and all detox drinks, while the lowest ∆TP00 values were obtained from FU. When the effects of resin composites, detox drinks, and time on ∆TP00 were analysed, a statistically significant difference was found (p < 0.05). Manufacturers recommend using detox drinks for 28 days. However, this period of use may affect the surface properties of restorative materials. Based on these data, we recommend careful use of detox drinks to prevent adverse effects on restorative materials.

Effects of polishing techniques on the surface roughness of acrylic denture base resins

Abrasive waterjet is a cool cutting technology with the ability to cut most of the difficult to cut materials. Average surface roughness value is a measure of surface finish of a manufactured product. Modeling of the average roughness value of aluminium–silicon carbide metal matrix composites by dimensional method technique is carried out for both cutting and deformation mode regions. Abrasive waterjet cutting experimentation is carried out on trapezoidal-shaped aluminium–metal matrix composites by varying the process parameters. The model results are in good relation with the experimental results for the cutting wear region. The deformation wear results have slightly more percentage of error in comparison with the cutting wear region. Average surface roughness value is measured along the depth of penetration with noncontact confocal microscope. The average results of the cutting and deformation wear region are considered for modeling.

In recent years, consumers have become increasingly interested in natural, biodegradable and eco-friendly composites. Eco-friendly composites manufactured using natural reinforcing filling materials stand out with properties such as cost effectiveness and easy accessibility. For these reasons, in this research, a composite workpiece was specially manufactured using eco-friendly jute fibers. Two cost-effective cutting tools were specially produced to ensure high-quality machining of this composite workpiece. One of these specially manufactured cutting tools was subjected to DC&T (deep cryogenic treatment and tempering) processes to improve its performance. At the end of the research, when the lowest and highest Fd (delamination factor) values obtained with DC&T-T1 and T1 cutting tools were compared, it was observed that 5.49% and 6.23% better results were obtained with the DC&T-T1 cutting tool, respectively. From the analysis of the S/N (signal-to-noise) ratios obtained using Fd values, it was found that the most appropriate machining parameters for the composite workpiece used in this investigation were the DC&T-T1 cutting tool, a 2000 rev/min spindle speed and a 100 mm/min feed rate. Through ANOVAs (analyses of variance), it was discovered that the most significant parameter having an impact on the Fd values was the spindle speed, with a rate of 53.01%. Considering the lowest and highest Ra (average surface roughness) values obtained using DC&T-T1 and T1 cutting tools, it was seen that 19.42% and 16.91% better results were obtained using the DC&T-T1 cutting tool, respectively. In the S/N ratio analysis results obtained using Ra values, it was revealed that the most appropriate machining parameters for the composite workpiece used in this investigation were the DC&T-T1 cutting tool, a 2000 rev/min spindle speed and a 100 mm/min feed rate. In the ANOVAs, it was revealed that the most significant parameter having an effect on the Ra values was the feed rate at 37.86%.

Purpose The aim of this paper is to optimize the machining parameters to obtain the smallest average surface roughness values during drilling of the carbon fiber-reinforced polymer (CFRP) composite material with abrasive water jet (AWJ) and analyze the damage of the delamination. Design/methodology/approach CFRP composite material had been fabricated having fiber orientations frequently used in the aerospace industry (0°/45°/90°/−45°). Three different stand-off distances (1, 2 and 3 mm), three different water pressures (1,800, 2,800 and 3,800 bar) and three different hole diameters (4, 8 and 12 mm) were selected as processing parameters. The average surface roughness values were obtained, and delamination damage was then analyzed using Taguchi optimization. Drilling experiments were performed using the Taguchi L27 orthogonal array via Minitab 17 software. The signal/noise ratio was taken into account in the evaluation of the test results. Using the Taguchi method, the control factors giving the mean surface roughness values were determined. Analysis of variance was performed using the experimental results, and the effect levels of the control factors on the average surface roughness were found. Findings It was found that water pressure and hole diameter had a higher effect on average surface roughness, while water pressure and stand-off distance were effective on delamination. Practical implications Owing to their excellent thermal and mechanical properties, the CFRP composite materials show greater potential for their applications in aircraft and aerospace industry. Originality/value The novel approach is to reduce cost and spent time using Taguchi optimization as a result of AWJ drilling the material in this fiber orientation ([0°/45°/90°/−45°]s, which is often used in the aerospace industry).

Introduction: The toothbrush is one of the most commonly used mechanical aids for plaque control, capable of removing plaque efficiently. However, improper toothbrushing habits can lead to tissue trauma, such as abrasion or gingival recession. The design of toothbrush bristles is one of the most common etiological factors for abrasion. Aim: To evaluate and compare the enamel surface abrasion produced by three different toothbrush bristle designs in conjunction with a standard dentifrice. Materials and Methods: In this in-vitro study conducted in the Department of Periodontics, Bharati Vidyapeeth Dental College and Hospital, Pune, Maharashtra, India, from June 2023 to January 2024, a total of 21 extracted human premolars were collected. After thorough cleaning, the teeth were stored in normal saline. The crown portions of the teeth were mounted on an acrylic resin base and profilometric analysis was performed to record the average enamel surface roughness (Ra) value. The teeth were randomly divided into three groups based on the toothbrush bristle design used for toothbrushing: Group A: Tapered bristle, Group B: End-rounded bristle, Group C: Flattrim bristle. Toothbrushing was carried out using a customised toothbrushing device and a standard dentifrice twice daily for six weeks. After six weeks, profilometric analysis was conducted again. Descriptive statistics were expressed as means and standard deviations. The comparison of enamel surface abrasion among the three different toothbrush bristle designs was performed using the One-Way Analysis of Variance (ANOVA) test, followed by the post-hoc Bonferroni test for pairwise comparison. In this test, a p-value less than or equal to 0.05 was considered statistically significant. All analyses were conducted using Statistical Package for the Social Sciences (SPSS) version 25.0. Results: The results showed significantly greater Ra values for Group C (flat-trim bristle: 0.13±0.06) compared to Group A (tapered bristle: 0.09±0.03) and Group B (end-rounded bristle: 0.04±0.02). Group B exhibited the lowest Ra value, indicating the least enamel surface roughness (p-value: 0.038*). Conclusion: Within the limitations of the study, stylus profilometer analysis demonstrated that the flat-trim toothbrush bristle design is more prone to causing enamel surface abrasion than the endrounded and tapered bristle designs. The end-rounded toothbrush bristle design causes minimal enamel surface abrasion and is safer to use as an effective mechanical plaque control aid.

AA 7075 T6 material offers important strength values and is easy to machining. In this respect, it is preferred on a wide scale in the industry. This study aimed to investigate the surface quality that occurs in the end milling of AA 7075 T6 material. For this, 3 different cutting speeds (40, 80, 120 m/min), three different feed rates (0.04, 0.08, 0.12 mm/rev), 2 different cutting depths (1 and 2 mm) were selected. The selected cutting parameters are combined with 2 and 4-flute end mills. As a result of the experiments, the average surface roughness (Ra) value was measured. The relations of Ra values with the cut parameters were determined. It was determined that Ra increased with increasing feed rate and decreased with increasing cutting speed. No significant effect of depth of cut was detected. Increasing the number of mouths increased Ra. The milling simulation was performed with the 3D cutting module in the Deform 3D software. 2 and 4 flute end mills are modeled, and the workpiece is defined to the software and the cutting parameters. Temperature, damage, stress, and cutting force outputs were estimated through simulations run at different cutting parameters. The predicted outputs and the experimental Ra outputs were interpreted and interpreted. Experimental outputs were supported by successfully applying milling simulation in Deform 3D software.

This study focused on the influences of drilling parameters on hole quality and thrust force in drilling of carbon fiber-reinforced polymer (CFRP) composite laminates via variable feed rate. Drilling experiments were carried out by using three different cutting speeds, feed rates and the qualities of tungsten carbide drill. Scanning electron microscopy and coordinate measurement machine were used for hole surface damage and diameter analyses, and also a portable instrument and 3D optical profilometer were utilized for surface roughness measurement. It was identified that thrust force (Fz), delamination factor (Fd) and average surface roughness (Ra) values attained in drilling processes by variable feed rate are lower than those of constant feed rate with average of 14%, 3% and 18%, respectively. Besides, the hole diameter (D) values obtained with variable feed rate in hole exit were higher than those of constant feed rate. Moreover, the higher Fz values were obtained with diamond-coated and TiAlN-coated drills than those of uncoated drill with 55% and 77%, respectively. The interactive influences of drilling parameters on machinability factors were evaluated via analysis of variance, and then, the most significant parameter was specified as the feed rate for Fd, just as the drill quality for Fz, Ra and D. According to the experimental and statistical results, we suggested that the novel drilling strategy is a significant alternative for the step hole and conventional drilling of CFRP laminates.

Effects of etchant concentration and process temperature in chemical milling of 430 stainless steel with FeCl3

Effects of mechanical polishing treatments on high cycle fatigue behavior of Ti-6Al-2Sn-4Zr-2Mo alloy

The main objective of this work is to develop a mathematical model to evaluate optimum sanding conditions of Europen black pine (Pinus nigra). Samples were sanded using different of grit size, feed rate, cutting speed and depth of cut. Average surface roughness (Ra) values of each type of specimens were measured employing a stylus type of equipment. Interaction between sanding parameters and surface roughness of the species were analyzed using Minitab software and response surface methodology. Based on the fi ndings in the work feed rate, cutting speed, grit size and depth of cut values of 5,39 m/min, 19,75 m/sec, 220 (grit size) and 9 mm were determined as optimum sanding conditions.

Chemical Mechanical Polishing (CMP) is an indispensible step in the Polishing of glass and ceramic surfaces. About 90% of semiconductor devices like integrated circuits (ICs) and Phase-change memory (PCM) device fabrication are done to attain globally planarized surface with good surface finish and excess material removal rate. One of the critical consumables in the CMP process is abrasive slurry containing both abrasives and chemicals acting together. To improve the chemical mechanical polishing performance, abrasive particles of Basic Colloidal silica was modified with Vinyl Tris(2-methoxyethoxy) silane (VTMS) through silanization reaction with surface hydroxyl group. The modified abrasive slurry exhibited a better dispersibility and stability in aqueous fluids which resulted in the improvement of surface finish in comparison to conventional process. The results of comparative study between pure basic colloidal silica slurry and modified slurry of VTMS + Basic Colloidal silica indicated a better surface finish quality with average Surface Roughness values(Ra) values in the range of 0.28 nm −0.41 nm on five samples when polished for four hours.

Titanium aluminides are being explored as potential materials for the aeronautical sector. However, their application is limited by the high costs of processing and their difficulties in machining. This research evaluates the effectiveness of the minimum quantity lubrication technique (MQL) on the turning process of Ti48Al2Cr2Nb aluminide in terms of tool wear, tool life, cutting forces, surface integrity, and temperature. It was found that MQL conditions can improve the process efficiency, reducing the thermally induced wear mechanisms and enlarging the tool life compared to dry machining. Furthermore, it allows the cutting speed to be incremented, leading to lower processing times. However, MQL seems to not be effective in the reduction of the strain-hardening effect near the machined surface and, although the number of microcracks is reduced, defect-free surfaces cannot be obtained. Moreover, similar microstructural alterations as for dry cutting were detected. The best cutting conditions in terms of surface quality were assessed using the central composite face (CCF) design and surface response methodology. Optimization of the surface roughness under industrially viable cutting conditions was achieved with an average surface roughness value, Ra, of 0.29 µm (feed rate of 0.05 mm/rev, a cutting speed of 54.6 m/min and a depth of cut of 0.125 mm).