Papers by Keyword: Sandblasting

Abstract: Zirconia is one of the materials used in prosthetic restoration because of its better physical, mechanical, chemical, and biological properties. The surface treatment for zirconia can be mechanical, with grinding, sandblasting, and laser or chemically, with silane and etching. The combination of chemical and mechanical surface treatment can increase the surface roughness so that the bonding with the resin cement also increases. The study aims to examine the zirconia surface roughness after different surface treatments. This study used 25 zirconia samples in 10x10x2 mm square-shaped, divided into five groups. Group 1 treats sandblasting as a control. Group 2 sandblasting then etching with 9.5% hydrofluoric acid at 25°C for 60 minutes. Group 3 sandblasting then etching with 9.5% hydrofluoric acid at 100°C for 1 minute. Group 4 etching with 9.5% hydrofluoric acid at 25°C for 60 minutes. Group 5 etching with 9.5% hydrofluoric acid at 1000C for 1 minute. The samples were cleaned with an ultrasonic cleaner and tested using a profilometer. The data test by using the ANOVA test and T-test. The highest surface roughness was the combination of sandblasting with 9.5% hydrofluoric acid etching at 25°C for 60 minutes. The lowest was 9.5% hydrofluoric acid etching at 100°C for 1 minute. ANOVA statistical analysis with a p-value <0.05 ((8.4051 x 10-12) indicates that the test was significant. The result of this study was the combination of surface treatments resulted in higher surface roughness. Duration of the etching time affected the increase of zirconia surface roughness.

Abstract: Titanium was the most commonly used metal in orthopedic implant. However, no direct chemical bond would be possible between the implant and surrounding bone tissue, and so the titanium implants lack the potential to induce rapid bone formation. Coating the titanium with a bioresorbable and osteoconductive layer would have a significant osseointegration. The purpose of this study was to fabricate and characterize calcium carbonate coating. The coating was fabricated on Ti substrate by converting of CaO coating in humidity environment under CO₂ flow. The CaO coating was deposited by sandblasting process. The CaCO₃ coating was approx. 1.85 µm thick and covered the surface’s surface uniformly. The coating strength was approx. 16.1 MPa and the Ca content in the coating was 2.02 mg/mm².

Abstract: The post-fabrication processes on CAD/CAM milled dental Zirconia result in surface roughening, micro-cracking, a decline in surface texture, and loss of strength. Also, the hydrothermal stresses formed due to water, blood, and synovial fluid infiltration into the crack space initiate crack propagation. The present work makes an effort to study the effect of surface morphology due to the post-processing of Yttrium-stabilized tetragonal Zirconia (Y-TZP) after CAD/CAM milling by studying the height, spatial, functional parameters (volume & Stratified surfaces), and 3-D surface roughness parameters in detail. Five groups based on post-processing combinations currently used in clinical conditions were selected for the study. Group 1(G1-S) involved the milling of pre-sintered blocks followed by sintering. Group 2(G2-S+P) consisted of sintering followed by the polishing process. Group 3(G3-S+P+S.B) consisted of sintering, polishing, and sandblasting with Aluminium Oxide (Al₂O₃) with a particle size of 110µm. Group4 (G4- S+S.B) involved sintering followed by sandblasting. Group5 (G5-S+S.B+P) consisted of sintering, sandblasting, and polishing. The surfaces were evaluated using a 3-D surface profilometer before and after wear. Before wear, the G4 process group responded with the highest surface roughness value, (Average roughness) Sa=1.378±0.409μm, and it was within the limit, which supported osseointegration. Valleys were predominant in almost all the groups, except G4. Also, the peak and core parameters for G3 &G4 were higher and will be of interest for further bone-implant contact (BIC) studies. The groups with sandblasting fabrication processes (G3, G4) exhibited relatively higher 3-D roughness parameters when compared to the groups with fabrication processes (G1, G2, G5). After wear, there was a considerable decline in the material peak. The research revealed that the methods with sandblasting could be suitable for osseointegration, BIC, and in-vivo performance for crown applications. Also, sandblasting followed by polishing (G5) was found to be optimal. Dentists will be able to determine the right clinical adjustments for their chairside CAD/CAM dentistry using 3-D surface roughness morphological analyses. It will also aid researchers in conducting in-depth studies on the issues related to oral cavity.

Abstract: The paper presents the results of measurement of resistance of concrete with surface treatment against water with deicing chemicals. Surface treatment of the test specimens was performed by sandblasting using steel balls. The effect of sandblasting was measured on normal strength aerated concrete (NC) and high strength concrete (UUHPC). Aerated concrete gains its resistance to water with deicing chemicals mainly due to its pores structures, while UUHPC due to the low porosity and low water absorption of the cement matrix. The sandblasting of the specimens simulated the required surface finish or mechanical deterioration of the concrete.

Abstract: Sandbalsting is a method used for surface treatment and at the same time this process also improves the mechanical properties of the material. ASTM A516 Grade 70 is widely used in industrial sector as it provides very good mechanical properties in tough conditions. The main usage of this material is in moderate and low operating services. This paper focus on the effect of sandblasting process on ASTM A516 Grade 70 on improving the mechanical properties and fatigue life of this material. Samples have been blasted with sand grade SAE G-80. The focus of this paper is the result of the microhardness, tensile and fatigue test before and after the sandblasting process to study the improvement in mechanical properties as well as the fatigue life. The research was extent to the microstructure analysis using SEM to study the change in microstructure after sandblasting process and fatigue test. Result shows that the hardness increases with respect to blasting time. Result also shows 2.3% increment in tensile strength after sandblasting and there is significant increment in fatigue life. Result also shows that the sandblasting process decreases the grain size of the material. It was proven that the sandblasting process will increase the hardness and decrease the grain size of the material with respect to sandblasting time. At the same time, there is a significant improvement in mechanical properties and fatigue life by applying sandblasting process on the tested material.

Abstract: The aim of this work is to investigate the effect of sandblasting and electropolishing on roughness and corrosion rate of AISI 316L stainless steel. The equipment used was sandblasting machine with a working pressure of 5-7 kg/cm2 with a duration of 10 minutes. The silica sand was used with size of 500-800 μm. The equipment used in the electropolishing process is the DC power supply with a maximum output of 2x100A. Anode and cathode material were AISI 316L stainless steel. Electrolyte solution consisted of 96% mass fraction of sulfuric acid and 85% mass fraction of phosphoric acid with a ratio of 1. The parameters used in the electropolish process were voltage, electrodes distance and electropolishing duration process. The combination of sandblasting and electropolishing cause the decrease in surface roughness by more than 28 times, from 3.17 to 0.11 μm. The decrease in the rate of corrosion on specimens that have been treated sandblasting and electropolishing by 37%. The optimum parameters for testing surface roughness and corrosion rate contained in the sandblasting process electropolishing for 10 minutes with a distance of 1 cm, duration 20 minutes and voltage 8V.

Abstract: In order to ensure adherence of the arc sprayed layer, on the metal substrate, a few specific operations must be performed: initial cleaning, degreasing, roughening, final cleaning and degreasing. At the moment, there are standards which refer to the degree of preparation for processing metal surfaces by spraying. Performing metallic surface preparation operations require compliance with specific health and safety measures and environment protection.

Abstract: The apatite-forming ability of zirconia ceramics subjected to various surface treatments was investigated. Zirconia samples (Y-TZP) in the form of disks and rods were sandblasted and chemically etched in strong acids (HF, H₃PO₄, H₂SO₄) and/or in NaOH solution at an elevated temperature. The surface properties were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), wettability and roughness measurement. The ability to form bone-like apatite on the surface was evaluated by immersion of the sample in simulated body fluid, which has ion concentrations nearly equal to the inorganic part of human blood plasma. The effect of applied surface treatment on mechanical properties was investigated. Sandblasting resulted in significant increase of roughness. Chemical etching in H₃PO₄ and H₂SO₄ caused reduction of contact angle but this effect was lost when subsequent alkali treatment was applied. Etching in NaOH, H₂SO₄ and two-step treatment combining H₂SO₄ or H₃PO₄ with NaOH resulted in the formation of bone-like apatite after immersion in simulated body fluid. These results indicate that sandblasted and chemically etched zirconia may be capable of direct bonding with living bone through an apatite layer created on its surface in a human environment. To avoid possible mechanical failure sandblasting conditions need further optimization.

Abstract: The oleophobic surface has extremely broad application prospects in industrial production and daily life. It can prevent the adhesion of materials and fouling, and prolong the service life. In this investition, an oleophobic surface on X70 pipeline steel specimen was prepared successfully by the combination of sandblasting, chemical etching, and low energy modification. The microstructure and oleophobicity of the surface were studied by scanning electron microscope (SEM), contact angle tester, and confocal microscope. The results showed that micro-nanocomposite structure on the specimen was formed after sandblasting and chemical etching of concentrated hydrochloric acid aqueous solution. The low-energy modification of perfluorooctanoic acid anhydrous ethanol solution just covered the surface, but had no obvious influence on the surface morphology. After chemical etching and low-energy modification, the specimen processed by sandblasting for 30s obtained the better oleophobicity, and the maximum contact angle between the surface and engine oil was 130°.

Abstract: When installing concentrator photovoltaic (CPV) systems in desert areas, we must consider the impact of sandstorms on the Fresnel lens in CPV modules. CPV systems are much more sensitive to sandstorms than flat-panel PV systems because they can only use the direct beam component of sunlight. In this study, the transmittance of a PMMA substrate after sandblasting was evaluated and the influence of sandblasting on the output of a CPV system was assessed. The transmittance of PMMA decreased with an increase in the momentum of blown sand. The conversion efficiency of a CPV module was determined by equivalent circuit calculation. The conversion efficiency decreased with increasing momentum. The coefficient of degradation was 0.17 point per unit momentum.