Mechanical strength of soda-lime glass sandblasted by gravitation

Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical strength.Sandblasting by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of inclination.To characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a profilometer.To determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular supports.The effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.

The Influence of Surface Morphology of Dense Ca-P Ceramics on Apatite Formation in Dynamic SBF

This study aimed at exploring the effect of surface morphology of dense phosphate calcimn （Ca-P） ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid （SBF）. Dense and sandblasted calcium phosphate ceramics were immersed into dynamic SBF flowing at normal physiological speed of body fluid of skeletal muscle. The changes were characterized using SEM, XPS, IR and XRD. Changes can be observed after the sandblasted surface of dense calcium phosphate ceramics had been immersed in SBF for 14 days. XPS analysis results showed that the flake-like structure was composed of Ca, P, C, O; IR analysis result of surface structure of samples showed that there were specific peaks for CO3^2-; XRD results indicated the decrease in crystallinity and the increase in amorphous structure. The rough surface was advantageous for the formation of bone-like apatite. Increasing the Ca^2＋, HPO4^2- concentration of SBF could also enhance the bonelike apatite formation. All the results demonstrated that local concentration is a key factor affecting nucleation.

Effect of cold working and sandblasting on the microhardness, tensile strength and corrosion resistance of AISI 316L stainless steel

The aim of this work is to investigate the effect of cold working and sandblasting on the microhardness, tensile strength and corro-sion rate of AISI 316L stainless steel. The specimens were deformed from 17% to 47% and sandblasted for 20 min using SiC particles with a diameter of 500-700 μm and an air flow with 0.6-0.7 MPa pressure. The microhardness distribution and tensile test were conducted and a measurement on the corrosion current density was done to determine the corrosion rate of the specimens. The result shows that the cold working enhances the bulk microhardness, tensile and yield strength of the specimen by the degree of deformation applied in the treatment. The sandblasting treatment increases the microhardness only at the surface of the specimen without or with a low degree of deformation. In addition, the sandblasting enhances the surface roughness. The corrosion resistance is improved by cold working, especially for the highly deformed specimen. However the follow-up sandblasting treatment reduces the corrosion resistance. In conclusion, the cold working is prominent to be used for improving the mechanical properties and corrosion resistance of AISI 316L stainless steel. Meanwhile, the sandblasting subjected to the cold worked steel is only useful for surface texturing instead of improving the mechanical properties and corrosion resistance.

实例介绍Sand Blaster(沙漠风暴)插件

在影视创作特技中,我们会经常看到变形这一技巧。通常的变形是针对模型本身所发生的,如模型本身发生凸凹、倾斜或扭曲等变化。另一种变形则是在两个不同的三维模型之间互相转变,这种技巧常被应用在很多的好莱坞大片特技上。以前,这类的变形特技都是在SGI等大型工作站上用专门的软件制作,而现在也可以在PC机上用3DSMAX的插件来模拟制作这类变形效果。由Digimation公司针对3DSMAX开发的SandBlaster(沙漠风暴)插件就可以制作变形效果。SandBlaster(沙漠风暴)是一个粒子插件,它的特点是使某个模型靠粒子形式转变成另一个模型。也就是说,原始模型先演变成粒子风暴形式,然后再由粒子风暴形式转变成另一个模型,通过这样的变化过程就完成了模型之间的转变。下面笔者将通过一个“人演变成狗”的实例来介绍如何使用SandBlaster(沙漠风暴)插件。

Bridge Maintenance Robotic Arm:Mechanical Technique to Reduce the Nozzle Force of a Sandblastine Rig

This paper describes a mechanical technique to reduce the nozzle reaction force of a sandblasting rig. A theoretical evaluation of the magnitudes and direction of action of typical sandblasting nozzle forces has been conducted and a technique for exploiting available energy in order to reduce the magnitude of the forces at the nozzle has been developed.Experimental results from a variety of tests in different configurations have confirmed the theoretically determined force magnitude’s accuracy and shown that forces of up to 106N can be present in typical sandblasting operations. The results have also shown that an up to 77% reduction of force at the nozzle can be achieved by applying the developed mechanicaltechnique.

Fuji "Sandblaster" 儿童自行车

Fuji “Sandblaster”系为一种价廉物美(市场售价仅为479马克)、不配备Stvzo(德国城市交通总则)所规定的装备件、规格为20英寸、专供少男少女使用的儿童MTB自行车新品。该车同样配有一种外观造型呈Y形、高度达28公分的钢制车架,可供少男少女从5岁起一直“享用”

Levi Strauss and H&M Announce Ban on Sandblasting

As a commitment to the health and safety of workers across the apparel industry, Levi Strauss & Co. and Hennes & Mauritz AB (H&M) announced plans to implement a global ban on sandblasting in all of their future

Improving the Surface Roughness of Dental Implant Fixture by Considering the Size,Angle and Spraying Pressure of Sandblast Particles

In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting angle.The surface treatment of the samples was performed using the SLA+Anodizing method.AFM testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each other.Then,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and speed.The results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a week.The simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state No.4.This will help prevent loosening of the dental implant fixture over time.

Erosion wear experiments and simulation analysis on bionic anti-erosion sample

The dorsal surface of a desert lizard has excellent particle erosion resistance.In this paper,a bio-inspired sample was designed and fabricated based on the biological characteristics of the dorsal skin of the desert lizard(Laudakin stoliczkana).The bionic sample consists of two materials with different characteristics,which form a two-layer composite structure.The particle erosion property and erosion wear mechanism of the bionic sample was studied by means of sandblast experiment and numerical simulation,respectively.The experimental results show that,in the stage with steady abrasion rate,the weight loss per unit time of the bionic sample is about 10%lesser than the control sample.The numerical simulation indicated that the two-layer structure of the bionic sample can efficiently absorb the normal stress,and dissipate the stress in the horizontal direction.Thus,the stress concentration on the sample surface is suppressed.The two-layer structure is contributed to the decentralizing of the stress distribution,and thus the occurrence probability of erosion damage can be decreased.

Surface and Subsurface Defects Studies of Dental Alloys Exposed to Sandblasting

The defects created in commercial dental alloys during blasting with alumina particles propelled in compressed air under pressure 0.1 and 0.4 MPa have been studied using positron annihilation spectroscopy, scanning electron microscopy and X-ray diffraction. It was observed that higher pressure causes the increase in roughness and damaged zone range. The type of defects was determined as vacancies on dislocations. The defect concentration decreases with the depth and depends on alloys' type and applied pressure. The Rutherford backscattering spectroscopy and variable energy positron beam studies indicate shallow alumina deposition in material and show that small pressure of 0.1 MPa is not enough to remove metal surface oxides completely in 60 s in all studied dental alloys.

Ductility of copper films on sandblasting polyimide substrates

Different surface morphologies of polyimide(PI)foils widely applied in flexible electronics were obtained using the technique of sandblasting.Copper(Cu)films were subsequently deposited on the treated surface of PI substrates.Upon tensile loading, the critical strain,crack density and count of cracks were measured to examine the ductility of Cu films on PI substrates.Obtained results show that after sandblasting treatment,the critical strain of Cu film decreases from 8.0%to 6.9%and,in comparison with the case without sandblasting,its surface crack density decreases remarkably,with no saturation of the crack density.The reduced crack density is attributed to the increase of contact area and interfacial adhesion after sandblasting,and whether the crack density is saturated or not is dependent upon the morphology of the cracks formed as a function of tensile strain.

Wear calculation of sandblasting machine based on EDEM-FLUENT coupling

Sandblasting machines are widely used in chemical,mechanical and other engineering fields.The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow,and impact by the continuous abrasive sand can cause the machine to wear or even fail.In this study,the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion,dynamic and collision characteristics of the sand.Air in the sandblasting machine was treated as the ideal gas and the continuous phase.The sand was regarded as the discrete phase solid in the computation.Using the Archard wear model,the wear amount of the sandblasting machine was calculated and the wear law was analysed,to provide a theoretical basis for optimising the design and operation method of the blasting machine.

Wear calculation of sandblasting machine based on EDEM-FLUENT coupling

Sandblasting machines are widely used in chemical, mechanical and other engineering fields. The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow, and impact by the continuous abrasive sand can cause the machine to wear or even fail. In this study, the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion, dynamic and collision characteristics of the sand. Air in the sandblasting machine was treated as the ideal gas and the continuous phase. The sand was regarded as the discrete phase solid in the computation. Using the Archard wear model, the wear amount of the sandblasting machine was calculated and the wear law was analysed, to provide a theoretical basis for optimising the design and operation method of the blasting machine.