Sandblasting Process Research Articles

Improving fatigue behavior of selective laser melted 316 L stainless steel by ultrasonic-assisted burnishing

PurposeIn this study, two postprocessing techniques, namely, conventional burnishing (CB) and ultrasonic-assisted burnishing (UAB), were applied to improve the fatigue behavior of 316 L stainless steel fabricated through selective laser melting (SLM). The effects of these processes on surface roughness, porosity, microhardness and fatigue performance were experimentally investigated. The purpose of this study is to evaluate the feasibility and effectiveness of ultrasonic-assisted burnishing as a preferred post-processing technique for enhancing the fatigue performance of additively manufactured components.Design/methodology/approachAll samples were subjected to a sandblasting process. Next, the samples were divided into three distinct groups. The first group (as-Built) did not undergo any additional postprocessing, apart from sandblasting. The second group was treated with CB, while the third group was treated with ultrasonic-assisted burnishing. Finally, all samples were evaluated based on their surface roughness, porosity, microhardness and fatigue performance.FindingsThe results revealed that the initial mean surface roughness (Ra) of the as-built sample was 11.438 µm. However, after undergoing CB and UAB treatments, the surface roughness decreased to 1.629 and 0.278 µm, respectively. Notably, the UAB process proved more effective in eliminating near-surface pores and improving the microhardness of the samples compared to the CB process. Furthermore, the fatigue life of the as-built sample, initially at 66,000 cycles, experienced a slight improvement after CB treatment, reaching 347,000 cycles. However, the UAB process significantly enhanced the fatigue life of the samples, extending it to 620,000 cycles.Originality/valueAfter reviewing the literature, it can be concluded that UAB will exceed the capabilities of CB in terms of enhancing the surface roughness and, subsequently, the fatigue performance of additive manufactured (AM) metals. However, the actual impact of the UAB process on the fatigue life of AM products has not yet been thoroughly researched. Therefore, in this study, this paper used the burnishing process to enhance the fatigue life of 316 L stainless steel produced through the SLM process.

Experimental Investigation of the Effect of Alternative Sandblasting Processes on the Surface Roughness Data of Smooth Rolls

The process of sandblasting is a method applied to remove oil, dirt, rust, and corrosion from metal surfaces, aiming to extend the metal's service life due to the gradual development of rust and corrosion over time. This procedure involves using various abrasive substances, specially manufactured under the name "grit." Sandblasting, similar to sandpaper, not only eliminates visible or micron-sized rust and corrosion on the metal surface but also aims to achieve a specific level of surface roughness. An essential criterion in this process is to texture the surface with appropriate abrasives.
 The sandblasting machine used in this study is designed to achieve the desired average surface roughness level, denoted by the R a value, on the smooth rolls in flour mill rolls and flaking rolls. The machine features a sand recycling system, a filtered vacuum suction line, and employs a blower system to provide a dust-free environment. The majority of the abrasive material sprayed by the nozzle is conveyed to the rear sand tank through vacuuming, allowing dust and abrasive material to accumulate in a closed tank without extensively mixing with the air. 
 
 Consequently, the operator can achieve abrasive material recovery through the blower method without being adversely affected by the sandblasting process. 
 The abrasive particles with a brown aluminium oxide property and a size of 24 mesh aim to create a homogeneous roughness on the surface of smooth rolls using a PLC system. In this study, the rotation of the roll bearings at a constant speed around their axis and the comparison of different surface roughness values with the variable linear velocity h of the nozzle positioned at different angles to this movement are investigated.

Optimization of surface roughness, phase transformation and shear bond strength in sandblasting process of YTZP using statistical machine learning

Sandblasting process is often applied to roughen the intaglio of yttria tetragonal zirconia polycrystals (YTZP) surfaces for easy and quality adhesion and micro-shear retention with dentine/resin cements. Sandblasting process parameters have shown to influence, at different scales, surface roughness, phase transformation and shear bond strength, all of which are referred, herein, as performance characteristics. This study aimed to find the parametric settings of sandblasting parameters that could simultaneously optimize these performance characteristics, hypothetically testing the probability. YTZP surfaces were sandblasted at different levels of incidence angle (IA), abrasive particle size (AP), pressure(P) and sandblasting time (ST) following the Taguchi method based on the two-level parametric process settings (L8(27)). Surface morphologies, roughness (SR), monoclinic content (MC), and shear bond strength (SS) were characterized by the SEM, average surface roughness, XRD, and shear bond strength tests, respectively. Rough surfaces containing scratches, plastic deformation streaks, micro cracks and pitting were observed. According to the Taguchi method, the same optimum sandblasting parametric setting maximized SR and MC but failed to maximize SS. Subsequently, the principal component analysis embedded in statistical machine learning was applied to find the optimum sandblasting parametric setting that maximized all the performance characteristics. The optimum sandblasting setting of IA = 45°, AP = 110 μm, ST = 20 s and P = 400 kPa predicted the maximum values of SR = 0.773 μm, MC = 36% and SS = 16.6 MPa. Analysis of variance confirmed AP and P as the most influencing parameters affecting all performance characteristics. Finally, these results provide a systematic and comprehensive route for optimizing sandblasting roughening of YTZP surfaces which can be adopted in adhesive dental and orthodontic industry.

Ti6Al4V-ELI Alloy Manufactured via Laser Powder-Bed Fusion and Heat-Treated below and above the β-Transus: Effects of Sample Thickness and Sandblasting Post-Process

Ti6Al4V-ELI is the most-used lightweight alloy in the aerospace industrial sector thanks to its high mechanical strength and corrosion resistance. The present paper aims, firstly, to evaluate the effects induced by different heat treatments, which were performed above and below the β-transus temperature on Ti6Al4V-ELI samples manufactured via Laser Powder-Bed Fusion in different orientations (XZ, XY, Z and 45°). The first set of tensile samples and bars were heat-treated at 1050 °C × 1 h, while the second and third set were heat-treated at 704 °C × 120′ following the AMS2801 standard specification, and at 740 °C × 130′. These heat treatments were chosen to improve the as-built mechanical properties according to the ASTM F3001 and also ASTM F2924-14 standard specifications. Optical and SEM measurements reveal primary, secondary and tertiary α-laths below the β-transus, while above this temperature, the microstructure varies in relation to the sample’s thickness. Secondly, this work analyzed the results obtained after a sandblasting process, which was performed on half of all the available heat-treated tensile samples, through XRD and Vickers microhardness measurements. XRD analysis also highlighted the presence of α2-Ti3Al and TiAl3 precipitates and the microstructural change in terms of the α-phase.

Study on the Modeling Method and Influencing Parameters of Sandblasting Process for Blade Grinding

Grinding the surface of wind turbine blades is one of the key production processes before its service. In order to solve the problem of high labor cost and low precision in manual grinding wheel grinding of wind turbine blades, the sandblasting process for blade grinding is proposed. The best parameters of sandblasting process applied to wind turbine blades are investigated by simulation. In this study, the simulation model of sandblasting process is established, and the fluid analysis of blades’ grinding using sandblasting process is carried out with the variables of blasting pressure, abrasive diameter, and blast distance. Simulation results show that the best parameters are 0.7 MPa for blasting pressure, 500 mm for spraying distance, and 0.4 mm for abrasive diameter. Finally, the tensile test is carried out on the samples’ grind by the traditional grinding process and sandblasting process. The results show that the paint surface grind by sandblasting process can bear a higher load. This study proves the feasibility of the sandblasting process in the composite materials’ grinding of wind turbine blades.

Evaluation of dust production efficiencies in sandy sediments

AbstractSeveral studies have shown that dust emission (vertical flux, F) can be considered a constant fraction (k) of the saltating flux (horizontal flux, Q), that is, . This coefficient of proportionality, or dust production efficiency factor, is often called the ‘k factor’ and is fundamentally related to soil properties especially soil texture. Beyond regional and global modeling applications, a practical utility of k is for air quality regulatory agencies where k can be used to estimate F based on only measurements of Q, which is more easily measured in the field. Only a few studies have directly estimated the k factor from soils within potential dust sources even though dust models that represent the sandblasting process typically utilize k. The goal of this study was to compare two methods to calculate k from sandy sediments and compare those estimates with an empirical method of calculating the k factor. The first method (method 1) used the difference between F calculated from two sets of sediment samplers whereas the second method (method 2) used a set of aerosol monitors to measure F. We found that the range of k values from our study are consistent with soil texture‐based estimates of k and also have the correct order of magnitude. Thus, any of the methods described in our study are appropriate for estimation of k for sandy soils.

Validation of the sandblasting process in the manufacturing of precision spheres for non-contact metrology

In order to ensure the measurements that can be made with non-contact metrology technologies, it is necessary to use verification and calibration procedures using precision artefacts as reference elements. In this environment, the need for increasingly accurate but also more cost-effective calibration artefacts is a clear demand in industry. The aim of this work is to demonstrate the feasibility of using low-cost precision spheres as reference artefacts in calibration and verification procedures of non-contact metrological equipment. Specifically, low-cost precision stainless steel spheres are used as reference artefacts. Obviously, in order for such spheres to be used as standard artefacts, it is necessary to change their optical behaviour by removing their high brightness. For this purpose, the spheres are subjected to a manual sandblasting process, which is also a very low-cost process. The equipment used to validate the experiment is a laser triangulation sensor mounted on a Coordinate Measuring Machine (CMM). The CMM touch probe, which is much more accurate, will be used as a device for measuring the influence of sandblasting on the spheres. Subsequently, the influence of this post-processing is also checked with the laser triangulation sensor. Ultimately, the improvement in the quality of the point clouds captured by the laser sensor will be tested after removing the brightness, which distorts and reduces the quantity of points as well as the quality of the point clouds. In addition to the number of points obtained, the parameters used to study the effect of sandblasting on each sphere, both in contact probing and laser scanning, are the measured diameter form error, as well as the standard deviation of the point cloud regarding the best-fit sphere.

A Study on TiO2 Surface Texturing Effect for the Enhancement of Photocatalytic Reaction in a Total Phosphorous Concentration Measurement System.

Powerful sunlight, a high water temperature, and stagnation in the water flow induce eutrophication in rivers and lakes, which destroys the aquatic ecosystem and threatens the downstream water supply systems. Accordingly, it is very important to perform real-time measurements of nutrients that induce algal growth, especially total phosphorus, to preserve and manage the aquatic ecosystem. To conduct quantitative analysis of the total phosphorus in the aquatic ecosystem, it is essential to perform a pretreatment process and quickly separate the phosphorus, combined with organic and inorganic materials, into a phosphate. In this study, the sandblasting process was used for the physical etching of the wafer, and photocatalytic materials were deposited on the surface with various roughness in order to improve the photocatalytic reaction surface and efficiency. The photocatalytic reaction was applied to combine the pretreated sample with the coloring agent for color development, and the absorbance of the colored sample was analyzed quantitatively to compare and evaluate the characteristics, followed by the surface increase in the photocatalytic materials. In addition, the pretreatment and measurement parts were materialized in a single chip to produce a small and light total phosphorus analysis sensor.

Testing the Sandblasting Process in the Manufacturing of Reference Spheres for Non-Contact Metrology Applications

To ensure that measurements can be made with non-contact metrology technologies, it is necessary to use verification and calibration procedures using precision artefacts as reference elements. In this environment, the need for increasingly accurate but also more cost-effective calibration artefacts is a clear demand in industry. The aim of this work is to demonstrate the feasibility of using low-cost precision spheres as reference artefacts in calibration and verification procedures of non-contact metrological equipment. Specifically, low-cost precision stainless steel spheres are used as reference artefacts. Obviously, for such spheres to be used as standard artefacts, it is necessary to change their optical behavior by removing their high brightness. For this purpose, the spheres are subjected to a manual sandblasting process, which is also a very low-cost process. The equipment used to validate the experiment is a laser triangulation sensor mounted on a Coordinate Measuring Machine (CMM). The CMM touch probe, which is much more accurate, will be used as a device for measuring the influence of sandblasting on the spheres. Subsequently, the influence of this post-processing is also checked with the laser triangulation sensor. Ultimately, the improvement in the quality of the point clouds captured by the laser sensor will be tested after removing the brightness, which distorts and reduces the quantity of points as well as the quality of the point clouds. In addition to the number of points obtained, the parameters used to study the effect of sandblasting on each sphere, both in contact probing and laser scanning, are the measured diameter, the form error, as well as the standard deviation of the point cloud regarding the best-fit sphere.

Quality improvement of SS 304 with variations in feed rate and spraying distance in semi-automatic sandblasting

Roughness and flatness are things to consider in metal coating and painting. Sandblasting is one method to get certain roughness on the surface of the material. Blasting that occurs in the process affects roughness, flatness, and deflection of the workpiece. The purpose of this study was to determine the effect of the sandblasting process on surface roughness and flatness in SS 304 stainless steels material using variations in feed rate and distance by applying a semi-automatic sandblasting process by controlling the nozzle motion. The spray feed rate variations were 20, 40, and 60 mm min−1 and the distance variations were 100, 200, and 300 mm. The results of the test show that the smaller the feed rate and the closer the spraying distance, the higher the roughness value and the greater the deflection that affects surface flatness. The highest value occurs at a feed rate variation of 20 mm/min and a distance of 10 cm with a surface roughness value of 1.268 µm and flatness with a deflection angle formed of 1.184° one-sided treatment. In spraying experiments on two sided, improved the surface flatness with the highest deflection angle that occurs at a feed rate of 20 mm/min and a distance of 10 cm with a value of 0.737°.

Modeling and Recipe Optimization of Anti-Glare Process Using Sandblasting for Electronic Display Glass

Recently, anti-glare (AG) surface treatment technology has been considered as a standard process to enhance the visibility of electronic display devices. For AG, the hydrofluoric acid (HF)-based chemical etch method is the most common approach for the current display glass industry. However, in order to overcome the environmental and durability degradation problems of the HF-based chemical etch method, this paper proposes an eco-friendly physical surface treatment technology using the sandblasting method. Based on the preliminary analysis results using the central composite design (CCD) method-based response surface modeling methodology (RSM), additional experiments and analyses were performed for process modeling and optimal process recipe generation. To characterize the sandblasting process, the mean value of haze was considered as the process output, and the pressure of the nozzle, the distance of the nozzle from the surface of glass, the glass feed rate, and the grit size of the abrasives were considered as process inputs. Based on the process model using the statistical response surface regression method and machine learning-based approaches, the proposed method can generate optimized process recipes for various haze targets of 10%, 20%, and 30%, with an average haze difference of 0.84%, 0.02%, and 0.86%, and maximum deviations of 1.26%, 1.14%, and 1.4%, respectively. Through the successful completion of this work, it is expected that the proposed surface treatment method can be applied to various products including mobile phones, tablet PCs, and windshields of vehicles.

Residual Stress Evolution in Zirconia (Y8%) Coatings During Atmospheric Plasma Spraying for Substrates Under Rotating Kinematic

Ceramics coatings produced by atmospheric plasma spraying (APS) on steel alloys parts involve high residual stress level that can affect the coating properties and integrity. Most of the experimental studies were focused on the stress evaluation into APS-produced coatings onto static targets. However, these studies have not been extended to stresses induced on rotating samples. Indeed, the thermal background and the deposition way onto a static target is different from a rotating one, resulting in indifferent coating residual stresses. The aim of this work is to estimate and understand the real-time stress evolution from the sandblasting process to the coating formation while the substrate is fixed at a rotating support thanks to a new system developed in the laboratory. Three different sources of stresses are analyzed in this paper: stresses induced by sandblasting, substrate heating, and splat quenching followed by the cooling down of the coating/substrate composite. Resulting stresses measurements are compared with after test ones made by incremental hole drilling.

Influence of Processing Parameters on Coating Removal for High Pressure Water Jet Technology Based on Wall-Climbing Robot

The shipbuilding industry is very important for many countries. As an essential process in the shipbuilding industry, surface preparation (or coating removal) is gaining more and more attention. The traditional process used for ship hull coating removal is a sand-blasting process, which is harmful to the environment and inefficient. Recently, high pressure water jet technology has been developed to replace the traditional sand-blasting process. However, there are still many technical problems to be solved. In this paper, one wall-climbing robot was developed to remove coating based on high pressure water jet technology. Coating removal experiments under various experimental conditions were carried out and the corresponding coating removal rate for each case was obtained and compared. In addition, numerical simulation based on Fluid software was conducted to observe the water jet process more visually. Results show that the processing parameters, including the water pressure, travelling speed, inclined angle, and stand-off distance, can greatly influence the coating removal effect. The optimal processing parameters are obtained to guide the application of the high pressure water jet technology based on the designed wall-climbing robot for the shipbuilding industry.

Fabrication of Bioactive Zirconia by Doubled Sandblasting Process and Incorporation of Apatite Nuclei

In this study, we aimed to introduce bioactivity to bioinert zirconia by performing sandblasting process and subsequently depositing apatite nuclei (AN), which are fine particles of calcium phosphate precipitated by raising pH of SBF, on the surface of the zirconia samples. By soaking the AN treated zirconia samples in SBF, hydroxyapatite formation was observed in 1 day and high hydroxyapatite-forming ability was attained.

Enhanced bioactivity of Si3N4 through trench-patterning and back-filling with Bioglass®.

Using a simple and innovative sandblasting process, disks of monolithic biomedical silicon nitride (β-Si3N4) were texturized with a matrix of regular, discrete square trenches with a total depth in the range of hundreds of microns. The process consisted of sandblasting Si3N4 substrates through a stainless-steel wire-mesh (150 or 200 μm) using abrasive silicon carbide powders (α-SiC, ∼40 μm) under 1,034 kPa (150 psi) of gas pressure. The depth of the porosities could be controlled varying both the treatment time and the distance from the surface. Part of the samples were then filled with 45S5 Bioglass® powders to improve the osteointegration and stimulate the production of bone tissue. Due to the increased macroscopic and microscopic roughness, biological testing using human osteosarcoma cells (SaOS-2) showed improved cell proliferation and greater production of both mineral (hydroxyapatite) and organic (collagen) phases on the patterned surfaces compared to untreated β-Si3N4 or to the biomedical titanium control samples. Both of these effects were further enhanced when the porosities were filled with Bioglass®.

Fabrication of bioactive titanium and its alloys by combination of doubled sandblasting process and alkaline simulated body fluid treatment

Fabrication of bioactive titanium and its alloys by combination of doubled sandblasting process and alkaline simulated body fluid treatment

Effect of sand-blasting on fatigue properties of 7N01 aluminum alloy

Certain high-speed trains often suffer from the erosion of wind-drift sand during the serving period. The present paper simulated this sand-blasting process with consideration of sand-blasting pressure, angle, distance and sand particle size representing different natural conditions. Results show that the grit size has the greatest influence on roughness and residual stress of the 7N01 aluminum alloy based on the orthogonal test. The samples after low intensity sand-blasting (LISB) were characterized by micro-hardness, surface morphology and fatigue test. Results show that the surface of the blasted sample was severely impinged in form of extruded ridges crater-like morphology, representing different roughness values. The LISB causes a similar spoon shape residual stress distribution along the depth direction and it also increases the hardness of the surface zone. Finally, the residual compressive stress plays an important role in the improvement of the fatigue life, and the increase of roughness can seriously shorten the fatigue life.

The effect of surface preparation on high temperature oxidation of Ni, Cu and Ni-Cu alloy

In the present paper, the analysis of polishing, grinding and sand-blasting processes on oxidation behavior of nickel, copper and Ni30Cu70 alloy has been performed for three different temperatures. Surface roughness has been analyzed using two methods: contact profilometer and fractal analysis. It has been proved that Ra parameter for sand-blasted samples is greater about one order of magnitude from ground and two order of magnitude from polished samples. Obtained mass gain plots after isothermal oxidation tests, SEM microphotographs and SEM/EDS analysis of the samples prove that morphology of the polished and ground samples does not vary significantly after oxidation at investigated temperatures, but differences in oxide layer thicknesses and mass gains were observed. Oxidized sand-blasted samples revealed that increased surface roughness and alumina intrusions remained in the surface after sand-blasting process change the oxidation process–mixed Al/(Ni, Cu or Ni-Cu) oxide is formed and separate Al2O3 particles are visible. Moreover, differences in thickness ratio of copper oxides: Cu2O to CuO on copper samples oxidized at 750 °C (26, 20; 29, 64; 43, 45 for polished, ground and sand-blasted samples, respectively) prove that surface preparation influence high-temperature oxidation of the samples by promoting new diffusion mechanism.

Utilisation of Copper Slag Waste and Heavy-weight Aggregates for Production of Pre-cast shielding Concrete Elements

Concrete as a versatile building material can provide physical and biological shielding against ionizing radiation. In addition to nuclear reactor covers, facilities requiring radiation protection are radiological and X-ray laboratories in hospitals or health centres. The function of radiation protection can be met by heavy-weight concrete, whose shielding properties are largely derived from the high-density aggregates. One of the possible construction methods of shielding walls in healthcare buildings is the use of pre-cast concrete blocks. For this purpose, research on a concrete having a density in the air-dry state of higher than 3200 kg/m 3 using barite, magnetite and basalt as coarse aggregate and copper slag waste (from by-product of the process of copper extraction by smelting) as fine aggregate has been performed. The copper slag waste has been used, among others, as an abradant in the surface sand-blasting process but after such usage it is considered to be a waste and as indicated by pilot research, it can be a good substitute for sand in concrete. Mechanical properties, water absorption and sorptivity of heavy-weight concrete so produced were compared with reference concrete prepared with crushed amphibolite as coarse aggregate and quartz sand as fine aggregate. The suitability of copper slag waste for making small pre-cast shielding concrete elements is confirmed. The compressive strength of heavy-weight concrete mixtures with copper slag waste was sufficient for the intended applications. The copper slag concrete had lower water absorption and sorptivity than concrete prepared with sand. An economic analysis of the costs of producing concrete with a density higher than 3200 kg/m 3 with or without copper slag waste showed that the copper slag concrete, regardless of the type of heavy-weight aggregate used, is clearly more economical than the concrete of the compositions reported in the literature containing similar coarse aggregates and sand as the fine aggregate. DOI: http://dx.doi.org/10.5755/j01.sace.22.1.20006

Effect of Surface Roughness on the Bonding Strength and Spring-Back of a CFRP/CR980 Hybrid Composite

Carbon fiber-reinforced plastic (CFRP), which is a light and composite material, has a higher specific strength and stiffness than metal materials. However, owing to its low elongation, it is vulnerable to local impacts such as collision. Therefore, hybrid composite materials that can overcome the disadvantages of homogeneous materials by bonding CFRP and metal materials are increasingly popular. In this study, a physical surface treatment sandblast process was applied on a high tensile steel plate (CR980) manufactured by cold rolling to form another surface condition, and the bonding strength with CFRP was measured. In addition, spring-back due to the manufacturing process of the CFRP and CR980 hybrid composite material bonded with different surface roughness was observed. The bonding strength and the spring-back angle of the CFRP/CR980 hybrid composite material tended to increase with the increase in the surface roughness.