Papers by Keyword: Surface Texture

Abstract: The hyper productive surface plastic deformation processing technology called as wide burnishing (WB) was developed in Russian Federation. The mechanics of new WB technology is different from the classic SPD technologies (rolling or burnishing). For example applied force during processing of burnishing is 150-300 N, of WB is 2500-5000 N due to condition of process implementation in mass production with limited processing time (3-4 turnovers of workpiece). WB also has a high degree of deformation due to a multiple deformation passes. To determine the optimal WB processing parameters single and double instrumental devices were implemented and tested. Specimens made of steel 40 and high-strength cast iron 75-50-03 were tested. Initial roughness of steel 40 specimen’s surface was Ra = 0.5 microns and high-strength cast iron was Ra = 0.85 microns. Results of surface texture parameters of processed parts such as surface roughness Ra of steel 40 and high-strength cast iron 75-50-03 under varying load values P and number of cycles (the number of workpieces revolutions during the period of burnishing) were acquired. It was established that the minimum Ra value of the processed surface correspond with values of P = 210 N/mm² for steel 40 and P = 410 N/mm² for high-strength cast iron 75-50-03 regardless of number of burnishing cycles. Plastic deformation mechanism (processing time and pressure on the surface) influences on the processed surface roughness formation. It is possible to assume that straining state forms at the optimal values of P in terms of achieving a minimum value of Ra in which the reached degree of hardening allows to minimize the height of the microscopic irregularities of the previous grinding processing. In this case there is no plastic flow of the metal surface layer.

Abstract: In this scientific article the recommendations for a three-dimensional surface roughness parameters determination of mechatronics elements are developed. First of all, the measurements for surface with irregular roughness were made, what led to the determination of a 3D roughness correlation function. On that basis correlation interval in two perpendicular treatment directions was calculated and associated with number of surface roughness uncorrelated points. Secondly, the surface roughness step parameters evaluation precision in two mutually perpendicular directions was analysed. Particular attention was paid to the roughness average step RSm in the treatment longitudinal direction. As a result, the recommendations for a 3D roughness parameters determination were prepared.

Abstract: The broaching process is widely used to generate irregular internal and external part features, therefore there is a demand for a broach with good broaching performance. Aiming at slowing broach surface wear degree and improving the tool life, this paper puts forward a inverted triangle textured broach which is based on the theory of metal cutting, friction study and contact mechanics. The broaching 45# steel load experiment was carried out. The broaching force and surface morphological changes were measured, and the cutting performance and wear characteristics of the textured broach tooth were analyzed by comparing with ordinary broach. Results show that the inverted triangle textured broach can reduce broaching load by 5%, and improve the response performance of broach for broaching load. The wear area and wear quantity of ordinary broach were larger than textured broach. The textured broach can greatly improve the cutting efficiency, reduce the tool wear and increase lifespan.

Abstract: Due to the increase of product complexity, 5 axes machining centers are becoming more and more important. Rotary tables are usually chosen for the 4th and 5th axis. Additional hydraulic or pneumatic mounting clamps are often needed on these tables. The feeding of the required media is realized by a so-called rotary manifold. For this application, commonly several rotary seals are used to seal the transmitted media. Different sealing materials, based on the carrier polymer PTFE, have been examined during this research. In tribological model tests, friction and wear characteristics have been investigated during an oscillating movement under dry run conditions and equal load spectrums (surface pressure). The counter running surfaces were specific textured as a result of various machining processes to research the effects of possible micro-and macroscopic patterning on the sealing system. The tribological behavior of the analyzed combinations and the topography of the counter surfaces have been evaluated.

Abstract: Surface texturing has been shown to reduce friction and increase the film thickness in various tribological applications (hydrodynamic bearings, mechanical seals, and cylinder-liner contacts). Studies have reported that surface-texture can reduce the resistance of sliding friction pair, increase the oil film thickness, increase the bearing’s capacity. Surface texture structure’s design and layout are very important, unfavorable design may lead to be counterproductive. In this paper, in combination with the 650mm seal structure, we are using the main design of groove type to seal the inner surface texture, so as to study the geometry structure and distribution's influence on seal property.

Abstract: In order to study the differences in load-carrying capacity of surface-textured soft materials and stiff materials, a theoretical hydrodynamic model considering elastic deformation is developed for numerical simulation analysis. Minimum oil film thickness at a certain load is computed as an index to evaluate the load-carrying capacity of textured sliding surfaces made of soft materials and stiff materials. The results show that the elastic modulus affects greatly on the load-carrying capacity. In the case of the surface texture with a dimple aspect of 0.05, textured soft materials has a higher load-carrying capacity than that of the stiff materials. In the case of the surface texture with a dimple aspect of 0.01 and only under high loads, textured stiff materials provides a better load-carrying capacity than that of the soft materials.

Abstract: Objective: This study aimed to evaluate the effect of surface texture mold by stainless steel (SS) mesh on Invisalign material friction coefficient. Materials and methods: Ten kinds of SS mesh were used to mold surface texture on Invisalign material. Experiments were conducted using a zirconia ball that slid against Invisalign material plates with different surface textures. In the experiments, the coefficients of friction under normal loads of 100, 200, and 300 g under dry and artificial saliva conditions were recorded. Results: The coefficient of friction was relative to the pore size and wire diameter of SS mesh. Conclusions: The Invisalign material coefficient can be effectively managed by the surface texture mold by SS mesh.

Abstract: The paper presents the contribution in engineering of surfaces particularly in surface texture of Austenitic Stainless Steels. The objective of the investigation was to determine the surface texture of austenitic stainless steel after turning with coated carbide tool point. The investigation included geometrical parameters of Surface Integrity for different technological cutting parameters in dry turning process of austenitic stainless steel. The article presents the surface roughness parameters with the roughness profiles (irregular slopes). The percentage of isotropic surfaces and Bearing Area of ​​Primary Model. Analyses were performed for variable cutting parameters. An Infinite Focus Measurement Machine (IFM) was used for the surface texture analysis. The study was performed within a production facility during the machining of electric motor parts and deep-well pumps.

Abstract: Surface texturing has become a technique to reduce friction and wear in cutting process; laser surface texturing is a method used to create micro-dimples on the interface surface. It is considered that cutting of titanium is difficult. As the experiments are costly and time demanding, metal cutting modeling provides an alternative way for better understanding of machining processes under different cutting conditions. In this paper a 3D finite element model has been used to simulate the cutting process of titanium alloy Ti6Al4V to predict the cutting forces and temperatures.

Abstract: Surface textures are one of a main criterion for reducing wear and friction between mating surfaces. Influence of the surface texture on the tribological properties of cutting tool material was studied. Linear grooves were textured on the High Speed Steel (HSS) by electro-discharge process using EDM. The HSS pins are wear-tested by pin-on disc wear test method using D3 die steel as disc component. The results show that textured surface shows less wear rate on comparing with non-textured surface even during high temperature and high load conditions. This effect on wear is mainly due to reduction in surface contact area between the mating wear surfaces also effective transfer of wear debris from the wear medium.