Lower Surface Roughness Values Research Articles

Integration of Thermal Infrared and Synthetic Aperture Radar Images to Identify Geothermal Steam Spots Under Thick Vegetation Cover

Identifying physical properties of geothermal features such as surface temperature and roughness is crucial for geothermal assessment, hydrology, and environmental studies. Surface temperature and roughness-related rock properties strongly influence the thermal infrared and back-scattering intensities, respectively, of synthetic aperture radar (SAR) images. This study aimed to identify geothermal steam spots based on the surface temperature and roughness of altered surfaces, mud pools, and hot springs in tropical conditions. The thermal emissivity separation method was adopted to calculate kinetic temperature using the thermal infrared (TIR) of the advanced spaceborne thermal emission and reflection radiometer (ASTER) data as well as ground temperature data. Surface temperatures calculated by the thermal emissivity separation method were corrected using measured ground temperatures to eliminate the effects of atmospheric absorption, thermal inertia of materials, and/or diurnal temperature in the images. In addition, the linear fitting method was applied to obtain the final surface roughness model based on the calculated determination coefficient (R2) between the initial surface roughness model derived by Sentinel-1A SAR and field data. The highest R2 between surface roughness values from Sentinel-1A SAR and field data were selected to calculate spatially the surface roughness of the Wayang Windu Geothermal Field, West Java, Indonesia. The satellite imagery and field measurements showed that surface temperature and roughness features correlate with each other, and high and low thermal features correlate with high and low surface roughness values, respectively. Accordingly, we integrated the TIR and SAR data to propose the thermal resistivity index (TRI) as an indicator of the hydrothermal fluid paths to the surface. Low TRI was encountered at geothermal features and intersections of subsurface faults, which indicated weak zones that radiate heat from the subsurface to the surface.

Fabrication and characterization of multifunctional thin multi-layer films for transparent conducting oxides

Dielectric/metal/dielectric (D/M/D) multi-layer thin films have been fabricated on a well-properly clean Mari-Enfield (commercial) glass substrate using an electron beam evaporation technique. In these three-layer nanostructures, different metals, i.e., Silver (Ag), Aluminium (Al), and Copper (Cu) have been selected as inter-layer while Hafnium oxide (HfO2) used as a dielectric material. The substrate temperature during fabrication was kept at 150 °C, and the overall thickness of these sandwiched structures was 25 nm, i.e., Dielectric =10 nm (top layer), Metal =5 nm (inter-layer), and Dielectric =10 nm (bottom layer). X-ray diffraction (XRD) and atomic force microscopy (AFM) was used for the structural and surface analysis, respectively. XRD patterns indicate that these D/M/D layers were poly-crystalline with monoclinic phase, while the crystallinity of Cu based films were relatively better than Al or Ag. AFM micrographs reveal the smooth surfaces with low values of average and/or root mean surface (RMS) roughness. Optical properties were measured by using UV/VIS/NIR dual-beam lambda-9 spectrophotometer. The better transmission (in the visible region) and reflection (in the near-infrared region) may be a favorable characteristic for energy-efficient applications, heat mirror, and transparent conductive oxide, etc. Using measured transmission and reflection, various optical constants such as refractive index, extinction coefficient, and energy losses, etc. have been calculated. The electrical properties of these multi-layer films were determined through Keithley-2400 source meter using a four-point probe method. Sheet resistance values for Ag, Al and Cu based films are 5.62, 5.75, and 6.23 Ω/square, respectively.

Surface integrity analysis of electrochemical machining of γ-TiAl alloys

Surface integrity is directly related to component performance and service life. Various characteristics of the surface integrity of the three typical γ-TiAl alloys by electrochemical machining (ECM) were studied, including surface morphology, 3D profile, surface roughness, cross section, microhardness, residual stress and element analysis. Two current densities 5 and 50 A/cm2 were selected for comparative experiments. The results show that the three γ-TiAl alloys exhibit their own unique morphologies at low current density, and there is severe localized corrosion on the machined surface, resulting in the rough surface. However, the three γ-TiAl alloys show very smooth surfaces at high current density. This result also shows that the surface roughness values of the three γ-TiAl alloys all decrease gradually with the current density increasing, in which the extruded Ti-48Al-2Cr-2Nb has lowest surface roughness value (about Ra 0.506 μm) at 50 A/cm2. It is found that the microhardness of the machined surface of the three γ-TiAl alloys all decreased slightly, with a decrease of about 10 HV compared with the matrix. The residual stress of the samples decreases slightly after ECM, and the influence of different current density on the residual stress is not obvious. Finally, it is also proved that ECM has no effect on the elements of the machined surface.

Surface modification of eco-friendly particleboard made from sorghum bagasse and citric acid sucrose adhesive

Eco-friendly particleboard made from sweet sorghum bagasse bonded with citric acid and sucrose was developed and met the minimum requirement of JIS standard. The surface roughness of particleboard which is important for coating with thin overlays, however did not measure yet. Therefore, the effect of particle size composition in surface modification of particleboard on the physical and mechanical properties of the panel was investigated. Sorghum bagasse has been used as raw materials in the manufacturing of three-layer particleboard. The composition of coarse particle (core layer) and fine particle (face and back layers) in the fabrication of particleboard was varied into four compositions such as A (0 (face): 100 (core): 0 (back), B (12.75:75:12.75), C (25:50:25), D (37.5:25:37.5)). Particleboard was bonded with 20 wt% of citric acid-sucrose (CAS) adhesive based on dry weight of particle and hot-pressing at 15 MPa and 200°C for 10 minutes. Dimension and target density of particleboards were 30 x 30 x 0.9 and 0.8 g/cm3, respectively. The physical and mechanical properties of the particleboard were evaluated according to JIS A 5908-2003. The Moisture Content (MC), Thickness Swelling (TS), Water Absorbtion (WA), Internal Bonding (IB) strength, Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) values of the particleboard satisfied the requirements for the type 8 JIS A 5908-2003 standard. The particleboard made of composition C had lowest value of surface roughness. The addition of fine particle ratio on the surface layer lowered the WA and TS of the particleboard and slightly increased the IB strength. Further, the MOE and MOR of the particleboard was not affected by increasing fine particles on the surface layer. This study suggests that particle size composition remarkably affects the physical and internal bonding strength of particleboard, while it has less interference to the mechanical properties.

Study of oil flow rates effects on lubricant oil behaviour during minimum quantity lubrication milling process

Minimum quantity lubrication (MQL) technology has been utilized extensively on these days as an alternative method to conventional cooling technique. A study to understand the know-how of tiny lubricant oil mists to effectively penetrate the cutting zone is important. However, such study is still scarce since the setup of the experimental probe during the machining process is on-going is difficult. The objective of this study is to analyse the lubricant oil film behaviour accumulated on AL6061 workpiece during MQL milling process by using a non-intrusive technique called as laser-induced fluorescence (LIF) method. The experiment was conducted under different oil flow rates to measure the thickness fluctuation of the lubricant oil film. Moreover, the surface roughness of workpiece after the milling process was also measured. As a result, the lubricant oil thickness was found to fluctuate in between 0.2 mm and 0.4 mm for two lower oil flow rates due to the tendency of evaporation. At higher oil flow rate, the lubricant oil fluctuated at higher thickness, i.e. 0.4 mm and 0.5 mm. On the other hand, the obtained mean surface roughness values did not reveal any remarkable difference from each other. However, lower mean surface roughness values were detected at 90 mm distance from machining starting point due to the accumulation of lubricant oil towards the end of workpiece. Therefore, the results of the oil behavior were successfully confirmed and thus MQL milling performance under different oil flow rates condition was clarified.

Analysis of the surface topography of retrieved metal-on-polyethylene reverse shoulder prostheses.

Despite the encouraging short- and medium-term clinical results and increased usage of reverse shoulder replacements, a higher revision rate is documented compared with other major joint arthroplasties. Adverse reaction to polyethylene wear debris is still an important factor which may influence the long-term survival of reverse shoulder arthroplasty. To date, only a small number of retrieval studies of reverse shoulder arthroplasty have reported the different damage modes on polyethylene components, but none have quantified the ex vivo surface roughness on both articulating surfaces. The main purpose of this study was to assess, for the first time, the surface roughness of 13 retrieved metal-on-polyethylene reverse shoulder replacements using a white light profilometre with nanometre resolution. Although no significant relationship was observed between the surface roughness values and patient variables, it was noted that half of the polyethylene components still showed their original machining marks, indicating little change in vivo and that the metallic humeral components in the reversed design configuration showed low values of surface roughness after their time in vivo.

Evaluation the Effect of Different Methods of Disinfection on Surface Roughness of Soft Denture Lining Materials

Aims: Aim of the study to evaluate the effect of two different disinfection methods for two periods of time on surface roughness of soft denture lining materials (Vertex and Molloplast-B). Materials and methods : The effect of two disinfection methods ,first chemical disinfection method (which include artificial saliva with saturated salt and artificial saliva with vinegar solution), and second microwave method on the surface roughness of soft denture lining materials for two periods of times (14 and 30 days) was evaluated, One hundred samples were prepared. ANOVA and Duncan,s multiple range test were performed to determine the significant difference among the tested groups at p ≤ 0.05% .Results: The results showed that the lowest value of surface roughness (Ra)value after 14 and 30 days for Vertex soft denture lining material was achieved with the microwave group, while the lowest value of surface roughness (Ra)value after 14 and 30 days for Molloplast-B was achieved with the distilled water. The highest value of surface roughness (Ra) for Vertex soft denture lining material was achieved with vinegar after 14 and 30 days., while for Molloplast-B was achieved with vinegar group after 14 days and with salt group after 30 days. Conclusion : The results of T-test Table showed that there were no statistically significant differences in surface roughness(Ra) value between Vertex and Molloplast -B soft denture lining materials after 14 and 30 days except for microwave group after 14 days at P value ≤ 0.05. Distilled water disinfection has less effect on the property than other chemical disinfection and microwave regimen. The effect of disinfection increase significantly with increasing period of time .

OPTIMASI KUALITAS KEKASARAN PERMUKAAN PADA PROSES ELECTROPLATING MATERIAL SS400 MENGGUNAKAN METODE TAGUCHI

Quality of product in various industries, especially in metal industry is the most attention so the product can compete and attract consumers. Surface roughness is one of the demand that must be fulfilled because it can be the initiation of cracks, especially when material receives recurring and fluctuating loading. Therefore, low surface roughness can produce a product with longer lifespan material. The goal of this study is to determine the most optimal combination of electroplating process with factors variety of voltage (volts), temperature (℃), and time of immersion (minutes) to produce a low values of surface roughness. This study uses an experimental design with Taguchi method. Contribution factors of control that produce the surface roughness values ​​were influenced significantly by control factor voltage (volts) amounted to 77.31% with an average roughness value of 1.29 μm. This is due to the increase in voltage which causes the deposition of electrolyte ions which is faster in the deposition structure of the specimen. Where as other control factors were not effected significantly on the temperature control factor amounted to 4.85% with an average roughness value of 1,32 μm. These results are possible because the temperature variations used (40℃ to 50℃) are still within the optimum operating temperature. And the other control factors is immersion time amounted to 10.13% with an average roughness value of 1,32. The result ware obtained because the length of coating time affected the quantity of deposition of nickel ions on the surface of the specimen. The result of optimal condition is the voltage level 2 (6 volts), the temperature at level 2 (45℃), and the immersion time at level 3 (25 minutes).

On the Assessment of Surface Quality and Productivity Aspects in Precision Hard Turning of AISI 4340 Steel Alloy: Relative Performance of Wiper vs. Conventional Inserts.

This article reports an experimental assessment of surface quality generated in the precision turning of AISI 4340 steel alloy using conventional round and wiper nose inserts for different cutting conditions. A three-factor (each at 4 levels) full factorial design of experiment was followed for feed rate, cutting speed, and depth of cut, with resulting machined surface quality characterized by resulting average roughness (Ra). The results show that, for the provided range of cutting conditions, lower surface roughness values were obtained using wiper inserts compared with conventional inserts, indicating a superior performance. When including the type of insert as a qualitative factor, ANOVA revealed that the type of insert was most important in determining surface roughness and material removal rate, with feed rate as the second most significant, followed by the interaction of feed rate and type of insert. It was found that using wiper inserts allowed simultaneous increases in feed rate, cutting speed, and depth of cut, while providing better surface quality of lower Ra, compared to the global minimum value that could be achieved using the conventional insert. These findings show that wiper inserts produce better surface quality and a material removal rate up to ten times higher than that obtained with conventional inserts. This clearly indicates the tremendous advantages of high surface quality and productivity that wiper inserts can offer when compared with the conventional round nose type in precision hard turning of AISI 4340 alloy steel.

Diamond turning on nitriding diffusion layer of pure iron

The nitriding diffusion layer has been considered wearing excessively during diamond turning due to its low nitrogen content in previous research. In this study, by increasing the gas flow rate during the cooling process, an extra needle-precipitates free phase sublayer with a thickness of 25 μm was formed beneath the compound layer, along with the traditional diffusion layer. The microstructure was analyzed and diamond turning test was carried out on each sublayer. After diamond turning all sublayers, no significant wear was observed on the diamond tool. The α-Fe(N) phase with supersaturated nitrogen atoms was found that it can inhibit the wear of the diamond tool. The needle-free precipitates phase sublayer had the lowest surface roughness value after diamond cutting, which was 6.10 nm.

INVESTIGATION OF SURFACE MORPHOLOGY OF DRILLED CFRP PLATES AND OPTIMIZATION OF CUTTING PARAMETERS

In this study, the carbon fiber reinforced polymer (CFRP) composite material was drilled using different parameters ([Formula: see text] and [Formula: see text] Point Angle, 30, 60 and [Formula: see text] cutting speed and 0.06, 0.08 and [Formula: see text] feed rate). Experimental parameters were designed according to full factorial design method and the results were analyzed using Taguchi L18 experimental design. The results of the study show that the lowest surface roughness values are 0.1958 and [Formula: see text]m with the cutting speed of 90 [Formula: see text] and feed rate of [Formula: see text] in the Point angles of [Formula: see text] and [Formula: see text], respectively. When the results of Anova analysis were evaluated, parameters (feed speed, cutting speed and end point angle) according to the effect ratios on surface roughness were formed at the rates of 41.06%, 33.13% and 5.07%, respectively. The most suitable parameters according to S/N ratios were determined using A2B3C1 factors for the average surface roughness.

Investigations on the Machining Performance using Solid Lubricant Mixed with Varying Proportions in Vegetable Oil during Hard Turning

The solid lubricant assisted machining is gaining more attention from last decade as use of cutting fluids becoming more and more prevalent around the world due to health and environmental concern. However, very few studies reported on use of solid lubricants during machining. With this view, in the present work, hard turning experiments with boric powder as a solid lubricant mixed with varying proportions in vegetable oil (refined sunflower oil) were performed using coated carbide tool. Machining performance in terms of surface roughness and cutting forces (tangential, feed and radial components of force) were investigated at different cutting conditions under dry and with three varying proportions of boric powder namely, 1%, 5% and 10% mixed with vegetable oil. It has been observed lower values of surface roughness and cutting forces when using solid lubricant assisted hard turning (SLHT) as compared to dry hard turning. Lowest values of surface roughness were observed when using 10% proportion of boric powder mixed with vegetable oil. However, cutting forces although observed to decrease with increasing percentage of proportion of boric powder in lubricating oil, no significant reduction; especially in tangential and feed components of forces, were observed when using 5% and 10% proportion of boric powder mixed with refined sunflower oil. SLHT experiments were also performed under mist lubrication (Mist-SLHT) with a view to assess the feasibility of variants of solid lubrication system in hard turning.

Tribological Assessment of Modified Jatropha Oil with hBN and Graphene Nanoparticles as a New Preference for the Metalworking fluid

Recently, manufacturing industries have concerned about the utilization of mineral-based metalworking fluids because of the numerous deleterious impacts on the health of workers and the environment as well as the shortage of mineral resources. Due to this scenario, the vegetable-based oils have emerged the researchers’ attention as a suitable replacement for the mineral based metalworking fluids since it is highly biodegradable, low toxicity and renewable resources. Nevertheless, the main problem of the utilization of the vegetable-based oils is that it shows poorer thermal and oxidative stability. The great development technologies had influenced the application of the nanofluids by adding the nanoparticles additives to the base oil as it gives better physical and properties, thus improved the tribological behavior. This study focuses on developing a new green synthesis and formulation of nanofluids from chemically modified jatropha oil by blending with nanoparticles additives such as hexagonal boron nitride (hBN) and graphene at the minimum concentrations (0.01, 0.025 and 0.05 wt.%). The physical testing such as kinematic viscosity, viscosity index and flash point were conducted and compared with commercial synthetic ester (SE). Then, tribological testing was performed by using four ball tribo test and analyses in terms of coefficient of friction, worn surface analysis and surface roughness. From the results, the sample of MJOs had showed an enhancement by providing higher viscosity index. The results demonstrate that MJOg2 provided the lowest coefficient of friction while MJOh3 and MJOg3 had smoother worn surface as it has lowest value of surface roughness in comparison with others sample. It can be concluded that the MJO samples have high potential substitution to mineral-based oil as a sustainable metalworking fluid in machining processes.

Optimization of Surface Roughness by Using Different Cutting Tools for Aluminum Alloy 6063

This research outlines an experimental study to determine the optimum parameter of cutting tool for the best surface roughness (Ra) of Aluminum Alloy (AA) 6063. For the experiment in this research, cutting parameters such as cutting speed, depth of cut and feed rate are used to identify the effect of both cutting tools which are tungsten carbide and cermet towards the surface roughness (Ra) of material AA6063. The machining operation involved to cut the material is turning process by using Computer Numerical Control (CNC) Lathe machine. The experimental design was designed by Full Factorial. The experiment that had been conducted by the researcher is 33 with 2 replications. The total number of the experiments that had been run is 54 runs for each cutting tool. Thus, the total number of experiments for both cutting tools is 108 runs. ANOVA analysis had been analyzed to identify the significant factor that affect the Ra result. The significant factors that affect the Ra result of AA6063 are feed rate and cutting speed. The researcher used main effect plot to determine the factor that most influenced the surface roughness of AA6063, the optimum condition of surface roughness and the optimum parameter of cutting tool. The factor that most influenced the surface roughness of AA6063 is feed rate. The optimum condition of surface roughness is at the feed rate of 0.05 mm/rev, cutting speed of 600 rpm and depth of cut of 0.10 mm. While the optimum parameter of cutting tool is cermet insert with the lowest value of surface roughness (Ra) result which is 0.650 μm.

Applicability of DLC and WC/C low friction coatings on Al2O3/TiCN mixed ceramic cutting tools for dry machining of hardened 52100 steel

The present work examines the applicability of DLC and WC/C low friction coatings on Al2O3/TiCN based mixed ceramic cutting tools for the dry and hard turning of AISI 52100 steel (62 HRC). The characterization of coated tools reveals that the coatings retain very low values of surface roughness, whereas the DLC coating exhibits much higher microhardness when compared to the WC/C coating. On the other hand, the WC/C coating exhibit a coarse surface morphology virtually due to the tungsten doping. Later, continuous turning tests were executed with the help of coated and uncoated cutting tools under dry cutting conditions, and their performance was investigated in terms of machining forces, cutting temperature and tool wear. Coating delamination by flaking and peeling is quite prominent in the case of both the coatings; however, it is less severe for the WC/C coated tool. The coatings help to reduce machining forces, cutting temperatures and tool wear, but the performance of coated tools converge towards uncoated tool as the cutting speed, and feed rate is increased. Both the coatings prevent the development of cracks near the cutting edge with WC/C coating exhibiting superior wear behavior basically due to its multilayered structure and better thermal stability. Moreover, the tested low friction coatings don't serve as thermal barriers and only the lubrication generated due to graphitization at the chip-tool interface is mostly responsible for the improved machining performance.

Effect of acidic/alkalinity slurry on titanium alloy CMP performance under different rotation speed condition

Aiming at the poor machinability of titanium alloy parts, the effect of slurry properties (acidic/alkalinity and volume ratio) on CMP performance were investigated. The results showed that the selected parameters all had an obviously effect on CMP performance. For acidic slurry case, smaller scratches and lower value of surface roughness (0.0645 μm) were observed, but the reverse sides were emerged with alkalinity slurry (0.0867 μm). Moreover, bigger material remove rate of the test sample was obtained with alkalinity slurry (7.4 102 m/min) than acidic case (5.56 102 m/min) especially in 80 r/min. A research conclusion is obtained that chemical reactions between titanium alloy and acidic slurry is easily produced. But, only corrosion action is existed for alkalinity condition which increases the brittleness and hardness characteristic of the sample surface. It is benefit for the increasing of material remove rate.

Machining performance enhancement of EN-31 diesteel using MWCNT mixed rotary EDM

The present study investigates the influence of adding multi-wall carbon nanotube (MWCNT) into the dielectric fluid of electric discharge machining (EDM) in terms of material removal rate (MRR), surface roughness (SR) and surface topology of EN-31 die steel using Cu electrode. A customized rotary electrode set-up has been developed to compare the performance improvement of powder mixed rotary electrical discharge machining (PMREDM) as compared to powder mixed electrical discharge machining (PMEDM) and conventional EDM. The present study attempts to investigate the optimization of process parameters of MWCNT mixed rotary EDM of EN-31 die steel using response surface methodology (RSM) and genetic algorithm (GA) in terms of MRR and SR. The optimization results show that MWCNT mixed rotary EDM shows highest value of MRR (9.72 mm3/min) and lowest value of SR (Ra = 2.03 μm), which are approximately 46.17% higher and 45.43% lower than conventional EDM values respectively. Further, various combinations of optimal values of MRR and SR and their corresponding input parameters setting have been shown in pareto table created by multi-objective optimization GA technique available in MATLAB. Finally, field emission scanning electron microscope (FESEM) analysis of MWCNT mixed rotary EDM and EDM surfaces is carried out which revealsthat MWCNT mixed rotary EDM shows better surface topography as compared to EDM process.

Optimization of machining parameters during the ECCDG of inconel 718 using PCA based grey relational analysis

Electrochemical cut-off diamond grinding (ECCDG) process is a hybrid machining process in which material is removed from the specimen by both electrochemical reaction and mechanical abrasive action. It is extensively used to machine electrically conductive but hard-to-cut materials such as nickel alloy, titanium alloy, tungsten carbide, metal matrix composites, super alloys etc. Inconel 718, a nickel based super alloy is difficult to machine with traditional methods due to its high strength and poor thermal diffusion. It is most productive material in aerospace industries. This paper concern with the optimization of process parameters during ECCDG process of Inconel 718 intend with to maximize material removal rate and minimize surface roughness. The optimization is done via a method known as principal component analysis (PCA) based grey relational analysis (GRA). A face centered central composite rotatable design of response surface methodology (RSM) has been used to plan the experimental runs on Minitab’17. Voltage, tool feed rate, electrolyte concentration, electrolyte flow rate and grinding wheel rotation are taken as process parameters to conduct the experiments on electrochemical cut-off diamond grinding setup. The ECCDG process is optimized to get the optimal level of parameters for higher MRR and lower surface roughness value. The optimized result indicates that the PCA based grey relational analysis approach has acquired the setting of optimal process parameters for the ECCG process as voltage = 11 V, tool feed rate = 0.18 mm/min, electrolyte concentration = 250 g/l, electrolyte flow rate = 6 l/min, and grinding wheel rotation = 1000 rpm. The ANOVA of OQPI model is done in order to check the acceptability of the developed model. The actual and predicted OQPI values are compared and the result shows 0.24% error which is within an acceptable range.

An in vitro study to compare the surface roughness of glazed and chairside polished dental monolithic zirconia using two polishing systems.

Aim:To evaluate the efficiency of two commercially available polishing systems in reducing surface roughness of a monolithic zirconia after clinical adjustment and to compare them to glazed zirconia.Setting and Design:In vitro study.Material and Methods:This in vitro study was conducted on 25 discs (10mm in diameter and 2mm in thickness) using monolithic zirconia (Ceramill Zolid). From 25 specimens, 5 specimens were randomly selected as the positive control. The remaining discs were abraded for 15 secs with a red band diamond finishing bur using an air rotor handpiece. Then the specimens were randomly divided into 5 equal groups of 5 specimens each. Group 1: Roughened, unpolished and unglazed. Group 2 (Positive Control): Glazed without prior roughening,Group 3: Roughened and polished with eZr polishing kit, Group 4: Roughened and polished with Optra fine ceramic polishing kit and Group 5: Roughened and glazed. The surface roughness (Ra) values (μm) were measured quantitatively by a surface analyzer. The mean values were compared using one-way ANOVA and Post Hoc Test. One specimen of each group was evaluated qualitatively under a scanning electron microscope(SEM) for surface topography.Statistical Analysis Used:One-way ANOVA and Post Hoc Test.Results:The lowest Ra value was found in Group 4-Roughened and polished with Optrafine ceramic polishing kit (Ra=0.47μm) as compared to Group 3-Roughened and polished with eZr polishing kit (Ra=0.49μm) and Group 5-Roughened and glazed (Ra=0.59μm). There was no stastistically significant difference between two polishing systems. SEM analysis of surfaces polished with Optrafine polishing kit revealed smoother and regular morphology as compared to surfaces polished with eZr polishing kit.Conclusion:The Optrafine polishing kit created more smoother and uniform surfaces as compared to surfaces polished with eZr polishing kit both quantitatively and qualitatively. Also, lowest surface roughness values were produced by optrafine ceramic polishing kit on monolithic zirconia as compared to glazed monolithic zirconia after their clinical adjustments.Thus Optrafine ceramic polishing kit can be used as alternative to glazing.

Experimental investigation on the effect of crystal orientation of diamond tooling on micro laser assisted diamond turning of zinc sulfide

The present article reports on an experimental study of the effect of crystallographic orientation of single crystal diamond on ductile material removal of ZnS. A multispectral ZnS workpiece was machined with single crystal diamond tools having two different configurations of cutting plane and cutting direction. An x-ray diffractometer (XRD) was used to evaluate the cutting plane and cutting direction of each tool. It was observed that the tools having a {100} cutting plane and <110> cutting direction resulted in considerably lower tool wear and surface roughness values, to that of tools with similar cutting plane orientation and <100> cutting direction.