Papers by Keyword: Surface Profile

Abstract: A three dimensional (3D) surface profiler, an X-ray residue stress tester, a potentiodynamic polarization approach and a damp heat test were employed to investigate the relationship between the rolling force (RF) and the corrosion resistance of interstitial-free (IF) auto sheet steels. The results show that the change of rolling force induces the variance of the surface topography and surface residue stress of IF steel. With the increasing RF, the corrosion resistance of IF steel in damp heat test can be enhanced, and the corresponding corrosion current density declines. Further, it is proved that the tensile stress on the surface can accelerate the corrosion rate of IF steel. As the compressive stress and the valley proportion on the surface increase, IF steel samples present a better corrosion resistance, because the compressive stress could retard the diffusion of corrosion media and the valley position possesses a lower electrochemical activity.

Abstract: The study mainly explores the surface profile of sapphire wafer after polishing by the method of chemical mechanical polishing (CMP). Pattern-free polishing slurry with SiO₂ abrasive particle is used to polish the sapphire wafer. This paper observes the phenomena of surface profile and surface scratches of sapphire wafer under different pressures and different rotational velocities during CMP. The study uses atomic force microscope (AFM) to scan the surface of sapphire wafer focusing on three axial lines of 0∘, 45∘and 90∘from the position of near edge passing the center of sapphire wafer. The study also selects five positions on a specific area to draw the surface profiles on the axial lines of 0∘, 45∘and 90∘. It can be observed that the central area of sapphire wafer has lower depression than other areas because the central area is polished more polishing times. Besides, the depression on the central area of sapphire wafer has a greater depression value and it has more and larger surface scratches when it is polished under a greater down force and at a faster rotational velocity.

Abstract: Accurate prediction of the material removal rate (MRR) distribution is very important for the control of the polishing process. However, the widely used prediction method of MRR based on the Preston equation is still incapable of predicting the roll-off phenomenon in polishing process. One of the reasons is that many of the researchers’ neglected the effect of the surface profile of the workpiece on the MRR. In this paper, the evolutionary process of MRR distribution with the change of surface profile using two different polishing pad is studied, it is found that MRR varies gradually with the change of surface profile and tends to be uniform finally. Based on the analysis of contact pressure considering the actual surface profile of workpiece and modified Preston equation, the distribution of MRR is analyzed. It is found that the Preston coefficient distribution on workpiece surface is stable when the surface profile variation is small and shows obvious differences from the center to the edge of the workpiece. Through the comparison it is found that correlation between the regularities of Preston coefficient distribution and the type of polishing pad is significant. The research results in this paper will play an important guiding role in the quantitative prediction method research of polishing process.

Abstract: Behavior of the material adhered to the cutting edge of a cermet insert was evaluated based on the profile of the machined surface in continuous turning of an austenite stainless steel SUS304. Height of the adhesion material decreased rapidly with increase of the cutting speed from 10m/min to 20m/min. The behavior of the adhered material was more stable than we expected. The adhered layer near the cutting edge was very stable, while the growth or breakage of the adhered material happened on the surface of the stable layer.

Abstract: To make the most of unique properties of diamond and to diminish an influence its disadvantageous properties new diamond tool composites with ceramic bonding phase (MAX) has been proposed. Ti₃(Si,Ge)C₂ and Ti₃SiC₂ were produced by self-propagating high temperature synthesis (SHS). 3-6 µm (MDA, De Beers) diamond powder was mechanically mixed with 10 wt% Ti₃(Si,Ge)C₂ or 30 wt% Ti₃SiC₂, pressed and the compacts were sintered at 1962 °C at 8.0 GPa in a Bridgman-type high pressure apparatus. These mechanical properties were determined: Vickers hardness HV1, Young’s modulus, tensile strength, fracture toughness and wear resistance. Microstructure and phase composition were studied by scanning and transmission electron microscopy and X-ray and electron diffraction techniques. To improve the final quality of the AlCu4MgSi(A) alloy, balls of diamond-new composites were incorporated into the burnishing tools. The influence of burnishing parameters, such as burnishing force and feed, on surface geometry parameters were measured and profilograms of the surface roughness recorded.

Abstract: A series of samples which have different surface roughness made by 45 steel were treated by Ultrasonic Deep Rolling (UDR), influence of original surface roughness on UDR effects, such as surface profile, surface roughness and residual stress, were studied. Results shows that surface roughness was reduced substantially through UDR treating and lager the original surface roughness, larger surface roughness and surface residual stress induced by UDR treating.

Abstract: This paper deals with surface roughness and surface profile in high precision methods of materials finishing. One of them is ELID process and the second method is grinding. There is surface profile and roughness compared of the three materials samples – carbide steel and two aluminium alloys. In the paper are shown results of surface measurement between ELID and ground surface. Both methods are very precision in the focus on surface roughness – measured units in nano scale. Paper shows possibilities in finishing methods for production, automotive, aerospace, medicine and cosmic industry.

Abstract: A new model based on multi-scale asperities is established in order to accurately describe flat profile error. After measuring the surface, surface points are projected to each cross-section according to three-dimensional coordinates. Graham’s Scan algorithm is used to search border points of each data set. Then minimum circum-circle is calculated and optimized. Asperity’s radius of curvature and coordinates is calculated by relationship of circle radius and section’s interval. In the assembly process, it is primarily that the peaks on surface actually contact. The contact error plane equation is determined by three asperities which can stability support the other part, so three proper asperities should be searched out firstly. Finally, experimental results show that this model can be applied to calculated contact error.

Abstract: We report a peculiar surface of poly(ethylene oxide) (PEO) film from droplet of water-PEO solution dried at heating substrate. The drying process contains two stages. The contact line is pinned initially. When substrate temperature reaches 60 °C, it starts to recede and continues to leave a film. The resulted film contains an edge-ring and middle-step surface profile. The rheological properties of PEO solution were studied. We found that capillary flow is dominant in the first drying stage and Marangoni flow appears because concentration gradient induced strong Marangoni effect and high temperature induced sharply decrease of viscous stress resulted in the contact line receding in the later drying stage. We confirm that the ringlike deposit is formed by outward capillary flow and the step in the middle is formed by Marangoni flow which carries solute to the inner, and these flows compete with the viscous force.

Abstract: This paper deals with new possibilities in aluminium alloys grinding. Presently the aluminium alloys have forceful usage in engineering. The using of aluminium alloys we can find in general engineering, automotive industry, cosmonautics, aeronautics and medicine. Wide possibilities of the aluminium alloys using is very important area for production technology too. The traditional process of aluminium alloys is e. g. forming, pressing. In cutting operation is it especially turning and milling operations. Grinding like finishing method of machining is not so used for aluminium alloys machining. This method not doing optimal results in touch with these materials of machined surface quality. This paper shows new ways and possibilities in aluminium alloys grinding.