A Model for Average Surface Roughness for Abrasive Waterjet Cut Metal Matrix Composites

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.

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).

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.

Surface roughness measurement using an optical system

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

The influence of a subnanosecond pulsed laser-based scribing of copper (Cu) and aluminum (Al) in salt solutions (NaCl and KCl) on the formation of microchannels is reported. This technique allows laser scribing along with selective etching of Cu and Al thin films. The focused laser beam can elevate the surface temperature on the sample and hence the chemical reaction rate, resulting in combined ablation with selective-area etching. The depth of microchannels in Cu and Al films is increased by 3–5 μm using the proposed hybrid technique. The average surface roughness values in the microchannel are decreased compared to that of scribing in water and air. The hybrid approach of laser-based scribing combined with electrochemical etching in neutral salt solutions allows uniform channel with almost no redeposit layer and debris on the channel edges. Further, an approach wherein, an application of direct current (DC) voltage (1.2 V) between the tool and the workpiece while laser scribing of Cu and Al in salt solution was demonstrated to improve the channel depth by few micrometers. This hybrid machining technique has also resulted in a reduction in the surface oxidation near the laser-ablated zone compared to that observed in air and water-based experiments.

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

The effects of diode and Er:YAG laser applications on the surface topography of titanium grade 4 and titanium zirconium discs with sand-blasted and acid-etched (SLA) surfaces

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.

Palm oil is among the most produced plant oils in the world and is solid at room temperature. This study aims to produce a palm oil-based lapping solution that contributes to sustainable manufacturing. A palm oil-based lapping solution was compared with grease and industrial lapping solutions. Lapping processes were conducted on cylindrical spur gear wheels following the Taguchi L27 experimental design, utilizing three distinct RPMs and varying times. The average surface roughness value after the lapping procedure diminished by 39.45% with the palm oil lapping solution, demonstrating greater effectiveness than the other treatments. The most significant percentage change among all lapping solutions was −59.06%, achieved with palm oil at 32 rpm for 10 min. On the other hand, the Taguchi L27 signal-to-noise analysis shows that the palm oil lapping solution yielded the optimal outcome at 50 rpm and 16 min. A palm oil-based lapping solution was seen as capable of replacing mineral oil-based lapping solutions.

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).

Novel short Agave americana based biocomposite and nanobiocomposites for automotive applications

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.

Effect of laser beam conditioning on fabrication of clean micro-channel on stainless steel 316L using second harmonic of Q-switched Nd:YAG laser