Sandblasting Research Articles

Adhesion-Related Phenomena of Stellite 6 HVOF Sprayed Coating Deposited on Laser-Textured Substrates.

The focus of this research is to examine the feasibility of using laser texturing as a method for surface preparation prior to thermal spraying. The experimental part includes the thermal spraying of a Stellite 6 coating by High Velocity Oxygen Fuel (HVOF) technology on laser-textured substrates. The thermal spraying of this coating was deposited both on conventional substrate material (low carbon steel) and on substrates that had been previously heat treated (nitrided steel). The properties of the coatings were analysed using scanning electron microscopy (SEM), optical microscopy (OM) and Raman spectroscopy. Adhesion was assessed through a tensile adhesion test. The results showed the usability of laser texturing in the case of carbon steel, which was comparable or even better than traditional grit blasting. For nitrided steel, the problem remains with the hardness and brittleness of the nitrided layer, which allows for the propagation of brittle cracks near the interface and thus reduces the adhesion strength.

The Effect of Shot Blasting Abrasive Particles on the Microstructure of Thermal Barrier Coatings Containing Ni-Based Superalloy

Grit particles remaining on the substrate surface after grit blasting are generally considered to impair the thermal performance of thermal barrier coatings (TBCs). However, the specific mechanisms by which these particles degrade the multilayer structure of TBCs during thermal cycling have not yet been fully elucidated. In this study, the superalloy substrate was grit-blasted using various processing parameters, followed by the deposition of thermal barrier coatings (TBCs) consisting of a metallic bond coat (BC) and a ceramic top coat (TC). After thermal shock tests, local thinning or discontinuities in the thermally grown oxide (TGO) layer were observed in TBCs where large grit particles were embedded at the BC/substrate interface. Moreover, cracks originated at the concave positions of the TGO layer and propagated vertically towards BC; these cracks may be associated with additional stress imposed by the foreign grit particles during thermal cycling. At the BC/substrate interface, crack origins were observed in the vicinity of large grit particles (~50 μm).

A preliminary study of the manufacturing of breech faces.

Firearm examiners may face challenges with subclass characteristics. Subclass characteristics have the potential to be confused with individual characteristics if a careful analysis for the presence of subclass characteristics is not performed. Several case studies are reported in the literature that discuss the presence of subclass characteristics and advise firearm examiners to disregard these characteristics for identification purposes. As far as can be determined, no fundamental study has been performed that explores the various methods used in firearm manufacturing and assess the potential of subclass characteristics being produced. In this study broaching, plunge milling, and lathe turning were used to produce consecutively manufactured breech faces for a Thompson/Center® (T/C®) Contender® G2 pistol. The breech faces were finished by tumbling or glass bead blasting. The 3D topographical scans of the breech faces were collected using a confocal microscope and then compared using the National Institute of Standards and Technology (NIST) congruent matching cells (CMC) algorithm. The results of this study demonstrated the presence of subclass characteristics after manufacturing by broaching and plunge milling. Lathe turning did not produce any subclass characteristics. ANOVA and Kruskal-Wallis H tests were used to determine significant differences between finishing methods within each manufacturing method. Significant differences were found in glass bead blasting versus tumbling and glass bead blasting versus no finish. No significant differences were found in no finish versus tumbling.

A Spectral-Based Blade Fault Detection in Shot Blast Machines with XGBoost and Feature Importance

The optimal functionality and dependability of mechanical systems are important for the sustained productivity and operational reliability of industrial machinery, and have a direct impact on its longevity and profitability. Therefore, the failure of a mechanical system or any of its components would be detrimental to production continuity and availability. Consequently, this study proposes a robust diagnostic framework for analyzing the blade conditions of shot blast industrial machinery. The framework explores the spectral characteristics of the vibration signals generated by the industrial shot blast for discriminative feature excitement. Furthermore, a peak detection algorithm is introduced to identify and extract the unique features present in the peak magnitudes of each signal spectrum. A feature importance algorithm is then deployed as the feature selection tool, and these selected features are fed into ten machine learning classifiers (MLCs), with extreme gradient boosting (XGBoost (version 2.1.1)) as the core classifier. The results show that the XGBoost classifier achieved the best accuracy of 98.05%, with a cost-efficient computational cost of 0.83 s. Other global assessment metrics were also implemented in the study to further validate the model.

Modeling Stochastical Particle Rebound based on High Velocity Experiments

Abstract Solid particle erosion is a major deterioration process which contributes to performance deterioration of modern axial compressors. The prediction of this deterioration process requires the correct computation of particle movement through the machine and their resulting impacts on the effected components. Especially for particles with high Stokes numbers the movement is determined mainly by the particle wall interaction, which is described by coefficients of restitution. Today, they are derived from experiments featuring high particle velocities and target materials, which are representative for turbomachinery applications. In this study, an already published rebound model is optimized for particle materials and velocities within high pressure compressors. The statistical spread of the rebound experiment is evaluated and the implementation into the rebound model is shown, which improves the prediction capability of the model. The model is implemented into a CFD software and numerical simulations are performed. The model is applied to a cylinder test specimen within a sand blast facility. The simulation shows the importance of the stochastics of the rebound, which is often neglected in particle wall models. Moreover, the numerical study shows requirements for the test specimen and its positioning in the experimental setup, which are prerequisites for the derivation of the coefficients of restitution using two dimensional particle evaluation equipment.

Impact of Different Surface Treatments on Shear Bond Strength between Two Zirconia Ceramics and a Composite Material.

The purpose of this study was to compare the surface changes and shear bond strength between a resin composite and two zirconia ceramics subjected to sandblasting and forming gas (5% H2 in N2) plasma surface treatment. Two types of zirconia ceramic specimens (3Y-TZP and (Y,Nb)-TZP) were divided into groups based on the following surface treatment methods: polishing (Control), sandblasting (SB), sandblasting and plasma (SB-P), and plasma treatment (P). Subsequently, chemical surface modification was performed using Clearfil SE Bond (Kuraray, Tokyo, Japan), and the Filtek Z-250 (3M, Maplewood, MN, USA) resin composite was applied. Shear bond strengths (SBS) and surface characteristics were determined. Plasma treatment was effective in increasing the wettability. For SBS, there were significant differences among the groups, and the (Y,Nb)-TZP and SB-P groups showed the highest bond strength. Similarly, for the 3Y-TZP specimens, the shear bond strength increased with both plasma and sandblasting treatments, although no statistically significant change was observed. In the P group, both (Y,Nb)-TZP and 3Y-TZP showed a significant decrease in shear bond strength with the resin composite compared to the control group.

Effect of surface treatment on oxidation film of 55SiCr spring steel wire

Abstract In this work, the surface pretreatments of 55SiCr spring steel wire rods were conducted using shot blasting and phosphating. After drawing, the steel wire was heated at 950°C × 15 s, followed by oxidation treatment with high-temperature steam or air for 3 seconds, and tempering treatment at 520°C. The effects of different surface treatment methods on the surface oxide film of spring steel wire were studied using stereomicroscopy, SEM, EDS, and XRD. The results showed that the steel wire surface oxide film with phosphating pretreatment was thicker and easy to fall off. The thickness of the oxide film formed by phosphating pretreatment samples increased by 2.1 um (high-temperature steam) and 0.3 um (air) compared to the shot-blasting samples under different oxidation atmospheres. High-temperature steam oxidation treatment significantly increased the thickness of the oxide film by 0.65 um (shot blasting) and 2.45 um (phosphating) under different surface pretreatment conditions. The outer surface of the oxide film turned black with high-temperature steam oxidation treatment and turned yellowish brown with air oxidation treatment. By both above oxidation treatments, the oxide film showed a multilayer structure, with enrichment of Cr and Si on the inner side.

EFFECTS OF HEAT TREATMENT ON THE IMPROVED WEAR RESISTANCE OF SHOT BLAST MACHINE BLADE MATERIAL

The blade is a component of the shot blast machine that functions as a thrower of small steel balls (steel shot). During its use, the blade undergoes impacts and friction with the steel shot, causing wear and a shortened lifespan. The material typically used for blades is white cast iron. Hence, the blade must possess good hardness and wear resistance. This study analyzed the causes of blade failure and proposed solutions in the form of hardening and tempering treatments. The tests conducted in this research included composition analysis, metallographic examination, hardness testing, and wear resistance testing. Based on the composition and hardness tests, the failure was attributed to material composition and hardness not meeting the ASTM A532 standards. The solution to this failure involves heat treatment to achieve hardness that complies with ASTM A532 standards, specifically hardening at 900°C for 40 minutes, followed by cooling with oil as the quenching medium. Then, the tempering process was carried out at 200°C, 250°C, and 300°C with holding times of 80 and 120 minutes. Post-heat treatment, the optimal hardness value, and the lowest wear rate were obtained at a tempering temperature of 300°C with a holding time of 120 minutes. The hardness value of the blade material under these conditions reached 63.8 HRC, and the wear rate was 1,21E-04 mm3.kg-1.m-1. A low wear rate indicates that the material has high wear resistance.

Dressing Mechanism and Evaluations of Grinding Performance with Porous cBN Grinding Wheels

Cubic boron nitride (cBN) grinding wheels play a pivotal role in precision machining, serving as indispensable tools for achieving exceptional surface quality. Ensuring the sharpness of cBN grains and optimizing the grinding wheel's chip storage capacity are critical factors. This paper presents a study on the metal-bonded segments and single cBN grain samples using the vacuum sintering method. It investigates the impact of blasting parameters—specifically silicon carbide (SiC) abrasive size, blasting distance, and blasting time—on the erosive wear characteristics of both the metal bond and abrasive. The findings indicate that the abrasive size and blasting distance significantly affect the erosive wear performance of the metal bond. Following a comprehensive analysis of the material removal rate of the metal bond and the erosive wear condition of cBN grains, optimal parameters for the working layer are determined: a blasting distance of 60 mm, a blasting time of 15 s, and SiC particle size of 100#. Furthermore, an advanced simulation model investigates the dressing process of abrasive blasting, revealing that the metal bond effectively inhibits crack propagation within cBN abrasive grains, thereby enhancing fracture toughness and impact resistance. Additionally, a comparative analysis is conducted between the grinding performance of porous cBN grinding wheels and vitrified cBN grinding wheels. The results demonstrate that using porous cBN grinding wheels significantly reduces grinding force, temperature, and chip adhesion, thereby enhancing the surface quality of the workpiece.

The Effect of Micromechanical Surface Preparation and Adhesive Surface Modification Strategies on Resin-Matrix Ceramic Repair Bond Strength Using Universal Adhesive Containing Silane Agent

Abstract Objectives This research assesses the effect of the different micromechanical surface preparations and chemically adhesive surface modification strategies applied to resin-matrix ceramics (Shofu Block HC) repaired using resin composites. Materials and Methods Eighty resin-matrix ceramics were conducted and designed into eight groups of 10 specimens and surface treated with (1) micromechanical preparation with sandblast (SB) or hydrofluoric acid (HF), and (2) chemically adhesive techniques with HC primer (HC) and/or silane (Si) and/or conventional adhesive (AD) or universal adhesive (UA) designing are as follows: group 1, SB + HC; group 2, SB + HC + AD; group 3, SB + HC + Si + AD; group 4, SB + HC + UA; group 5, HF + HC; group 6, HF + HC + AD; group 7, HF + HC + Si + AD; and group 8, HF + HC + UA. An ultradent model was put on the specimen center, then filled resin composite. Mechanical testing instrument was used to determine the samples' microshear bond strength (MSBS). To inspect failure modes, a stereomicroscope was used for observing the debonded surfaces. Statistical Analysis To assess the data, a one-way analysis of variance was employed, and the significant level (p < 0.05) was established with Tukey's test. Results Group 3 (29.29 ± 2.58 MPa) and group 4 (28.34 ± 1.26 MPa) demonstrated the two maximum MSBS values. The minimum MSBS (10.02 ± 3.31 MPa) was discovered by group 5. Nevertheless, group 2's MSBS values (22.78 ± 2.44 MPa) differed significantly from the values for groups 3 and 4. All the fractured samples in groups 1, 5, 6, 7, and 8 had an adhesive failure pattern. Furthermore, group 3 presented the greatest mixed failures (40%). Conclusion The SB is the most effective protocol for producing micromechanical retention. The application of HC primer and Si agent prior to the adhesive agent is the best chemical adhesive strategy for sandblasted resin-matrix ceramic surfaces. Additionally, the application of HC primer before the use of UA containing acid-resistant Si is the best alternative chemical adhesive strategy for improving the MSBS.

Effect of Silane-Containing Adhesives on Repair Bond Strength between Fresh and Aged Composite Materials-A Pilot Study.

This study investigated the effects of different surface treatments and a silane-containing adhesive on the repair bond strength between fresh and aged resin composites. A total of 140 composite specimens were prepared and aged for 24 h or 4 months. Each group was subdivided into seven subgroups (n = 10) depending on the surface treatment (no surface treatment (NT), sandblasting (SAND), or Sof-lex coarse disc (DISC)) in combination with the use of the silane-containing adhesive ScotchBond Universal Plus (SBU) or an adhesive without silane Prime&Bond Universal (P&B). The same composite was used for the repair as for the primary specimen. Specimens were dark stored in distilled water at 37 °C for 28 days. Shear bond strength was tested at a crosshead speed of 0.5 mm/min. The Kruskal-Wallis test with Bonferroni's post-hoc adjustment (α = 0.05) and the Mann-Whitney U-test were used for the statistical analysis. The results are shown as the median with the interquartile range. The highest bond strength (MPa) was achieved after 24 h in the DISC+P&B (20.39(16.85-28.83)). In the fresh 24 h group, the SAND+P&B (12.25(8.28-15.05)) and DISC+SBU (18.37(15.16-21.29)) were statistically similar. In the 4-month groups, both adhesives and surface treatments performed similarly. The NT, SAND, and DISC groups without adhesives had the lowest bond strength. In the repair of fresh or aged composite, the silane-containing adhesive SBU was not superior to the adhesive without the silane (P&B).

Effect of post-processing treatments on surface roughness and mechanical properties of laser powder bed fusion of Ti–6Al–4V

This study focuses on enhancing the surface characteristics of Ti–6Al–4V alloy fabricated through laser powder bed fusion (LPBF), a prominent additive manufacturing technique. The primary objective is to assess the impact of post-processing surface treatments on the surface roughness, microstructure, and mechanical properties of LPBF Ti–6Al–4V. As-built specimens with fully dense structures underwent sandblasting (SB), chemical etching (CE), and a combination of sandblasting and chemical etching (SB + CE). The investigation reveals significant variation in the surface morphology of as-built samples, primarily influenced by factors such as spattered particles, powder adhesion, and the stair-step effect. In the as-built condition, the down-skin exhibited the highest particle adhesion, covering 11.9 % of the surface. Sandblasting proved particularly effective in removing adhered particles, reducing surface roughness to 5.1 μm from an initial value of 17.8 μm for the down-skin surface. Furthermore, combining sandblasting and chemical etching was more effective than chemical etching alone in achieving uniform surface profiles. Tensile testing indicated that while the ultimate tensile strength remained unchanged, the strain at break significantly improved from 4.8 % to 11.5 %, representing a noticeable increase in ductility in post-processed samples compared to as-built conditions. These findings underscore the influence of post-processing treatments in mitigating surface roughness and enhancing ductility without compromising mechanical strength.

Effect of Bond Coating Surface Morphology on the TBC System Lifetime

A study on the effect of bond coating (BC) surface modifications prior to ceramic deposition is presented. Grit blasting and polishing were used to modify the BC surface finish. Thermal barrier coating (TBC) systems were made of a commercial yttria-stabilized zirconia (YSZ) deposited by electron beam physical vapor deposition on a β-(Ni,Pt)Al-coated Ni-based single crystal superalloy. Surface roughness measurements and scanning electron microscopy observations, before and after thermal cycling at 1100 °C, were performed to investigate the influence of the initial surface treatment on the YSZ/BC interface morphology and top coat spallation resistance. Surface states enhancing TBC spallation resistance have been found. In particular, it is shown that rumpling can be avoided even in the presence of phase transformations in the BC, by grinding samples with P600 SiC paper or by applying an “heavy” grit blasting leading to a thinner BC.

Evaluation of the anticorrosive painting procedure with reused abrasive for surface preparation – a case study

Atmospheric corrosion is a relevant cause of failure for many metallic structures. Its aggressiveness depends on environmental factors such as relative humidity, salinity, and contaminants. Anti-corrosion paint is the most used technique to minimize this problem, and surface preparation is a fundamental step for suitable paint adhesion. Abrasive blasting can remove oxides and old paint and texture the surface for receiving a new coating. An alternative to reduce costs is reusing abrasive particles to make the process more sustainable. In this investigation, an paint system was qualified through tests in its current environment. The influence of reused abrasives on the painting process by the paint layer’s thickness and its adhesion to the substrate was evaluated. Samples blasted with new and reused abrasives were prepared to evaluate the surface preparation process, allowing surface roughness measurements and incrustation analysis. It was possible to observe that the layers of paint were thin and not uniform, had approximately 155 μm thick, and defects such as pinholes. Reusing the abrasive did not affect the surface average roughness, which was 9.4 ± 2.5 μm. Abrasive incrustation and other contaminants such as Na, P, K, S, and Cl were found on new and reused abrasive surfaces. Recommendations for improvement and suggestions for changing the process were possible to assess.

Multiple sliding contact of viscoelastic solids: Modelling and experiments

Abstract The paper presents the results of friction tests of paving slabs in contact with rubber. The roughness of the slabs surface is formed by shot blasting. Some of the samples were slightly polished to simulate wear. The results of roughness measurement were adopted for modeling and used to calculate the effect of surface treatment on the deformation component in sliding friction. The results of modeling and experiments at room temperature have shown that a change in surface roughness affects the deformation mechanism of sliding friction. Static friction of slabs in contact with rubber was also studied in experiments. It is shown that the deformation mechanism of friction in the contact of paving slabs with rubber increases with an increase in the height (Sa, Ssk, Sku) and hybrid (Sdq) roughness parameters. A comparative analysis of friction maps at temperatures from −25 to +60°C was made for samples differing in surface treatment.

Effect of grit blasting on fatigue behavior of 2024-T3 aero Al alloy

Aiming at the removal of native oxide film on 2024-T3 Al alloy before plasma electrolytic oxidation, the methods to reduce the fatigue damage caused by grit blasting are explored. Effects of the grit size and pressure on surface roughness, residual compressive stress (RCS), and fatigue life of the Al alloy are studied. Increasing grit size and pressure leads to the increase in the surface roughness and RCS. Based on the theorem of momentum and tool cutting principle, mechanism of the grits on the craters and RCS is revealed. It is found that the angularness of the small-sized grit results in the formation of long scratches. The grit with high kinetic energy induces the large craters and high RCS. The craters are the primary fatigue crack initiation source. Moreover, the craters with long scratch and large height lead to the premature fatigue failure of the grit blasted specimens. However, Fatigue behavior is insignificantly affected by the RCS. The results provide new insights into the fatigue deterioration mechanism and life optimization of the grit blasted samples. Consequently, a parameter optimization scheme for the fatigue life of the grit blasted Al alloy is proposed.

From surface to success: How implant surfaces shape osseointegration

The field of dental implantology has significantly advanced to address the multifaceted impacts of tooth loss, encompassing physical, functional, emotional, psychological, and social dimensions. Dental implants serve as reliable solutions, ensuring stability, minimal bone loss, and absence of pain or infection. Central to their success is the surface modification of implants, which profoundly influences osseointegration—the process crucial for establishing a functional bond between bone and implant. This review explores various physical modifications of dental implant surfaces, focusing on macro, micro, and nano-level alterations. Macro-level modifications optimize implant geometry and thread design to enhance initial stability and long-term fixation. Micro-level modifications, including grit blasting and acid etching, increase surface roughness to facilitate mechanical interlocking and cell adhesion. Nano-level modifications, such as hydrophilic coatings and bioceramic enhancements, enhance surface energy and promote osteoblastic differentiation, thereby accelerating osseointegration. These surface modifications represent a critical frontier in implant dentistry, promising improved clinical outcomes and patient satisfaction through enhanced integration and reduced healing times.

Influence of the Surface Topography of Titanium Dental Implants on the Behavior of Human Amniotic Stem Cells.

The dental implant surface plays a crucial role in osseointegration. The topography and physicochemical properties will affect the cellular functions. In this research, four distinct titanium surfaces have been studied: machined acting (MACH), acid etched (AE), grit blasting (GBLAST), and a combination of grit blasting and subsequent acid etching (GBLAST + AE). Human amniotic mesenchymal (hAMSCs) and epithelial stem cells (hAECs) isolated from the amniotic membrane have attractive stem-cell properties. They were cultured on titanium surfaces to analyze their impact on biological behavior. The surface roughness, microhardness, wettability, and surface energy were analyzed using interferometric microscopy, Vickers indentation, and drop-sessile techniques. The GBLAST and GBLAST + AE surfaces showed higher roughness, reduced hydrophilicity, and lower surface energy with significant differences. Increased microhardness values for GBLAST and GBLAST + AE implants were attributed to surface compression. Cell viability was higher for hAMSCs, particularly on GBLAST and GBLAST + AE surfaces. Alkaline phosphatase activity enhanced in hAMSCs cultured on GBLAST and GBLAST + AE surfaces, while hAECs showed no mineralization signals. Osteogenic gene expression was upregulated in hAMSCs on GBLAST surfaces. Moreover, α2 and β1 integrin expression enhanced in hAMSCs, suggesting a surface-integrin interaction. Consequently, hAMSCs would tend toward osteoblastic differentiation on grit-blasted surfaces conducive to osseointegration, a phenomenon not observed in hAECs.

Effect of Different Surface Treatments as Methods of Improving the Mechanical Properties after Repairs of PMMA for Dentures.

Denture fractures are a common problem in dental practice, and their repair is considered a first option to restore their functional properties. However, the inter-material resistance may become compromised. Typically, the bond between these materials weakens. Therefore, various surface treatment methods may be considered to enhance their mechanical properties. Poly(methyl methacrylate) (PMMA) heat-polymerized resin (HPR) was used as the repaired material, cold-polymerized material (CPR) for the repairs, and different variants of alumina abrasive blasting (AB), methyl methacrylate (M), ethyl acetate (EA), methylene chloride (CH), and isopropyl alcohol (IA) treatments were applied. Finally, combined surface treatments were chosen and analyzed. Surface morphologies after treatments were observed by scanning electron microscopy and the flexural, shear, and impact strengths were tested. AB and chemical treatment with CH, M, and EA was used to improve all mechanical properties, and further improvement of the properties could be achieved by combining both types of treatments. Varied changes in surface morphologies were observed. Treatment with IA yielded less favorable results due to the low impact strength. The best results were achieved for the combination of AB and CH, but during the application of CH it was necessary to strictly control the exposure time.

Influence of operational properties of process lubricant on the surface quality of calibrated rolled products after shot blasting

Influence of operational properties of process lubricant on the surface quality of calibrated rolled products after shot blasting