Advanced Materials Research Vols. 69-70

Abstract: To evaluate the characteristics of semi-fixed abrasive plate (SAP), several parameters and relevant measurement methods are developed. The characteristic parameters include shore hardness, compression ratio, resilience ratio and shear strength. Five semi-fixed abrasive plates are manufactured with different bond concentration. The test results of five characteristic parameters of the SAP show the shore hardness, resilience ratio and shear strength increase, and compression ratio decreases with the bond concentration increasing. This test can provide instructive guides to the manufacture of SAP which can fit different occasions by changing the concentration of adhesives.

Abstract: The hybrid journal bearing with the high rigidity and rotation accuracy has been used in super-high speed grinding machine in some cases. But the main shortcoming of hybrid journal bearing is the higher temperature rise in the oil film when bearing works, which can lower the bearing capacity and cause the bearing failure due to the drop of oil viscosity and the larger thermal deformation. Fluent is a special CFD soft to simulate and analyze the flow and the heat exchange of liquid in the complex geometrical field. In this paper, the simulations of the temperature field of the oil film in the super-high speed hybrid journal bearing were performed by Fluent based on the mathematical models. The simulation results can not only forecast the flow state and the thermal properties of the bearing oil, but also find the design limitation of the bearing for the more improvement of the bearing design.

Abstract: In the cutting process, cutting force is one of the important physical parameters, which affects the generation of cutting heat, tool life and surface precision of workpiece directly. In this paper an orthogonal design of experiment and subsequent data is analyzed using high speed finish hard cutting GCr15 whose hardness is 65HRC. Cutting speed is 200-400m/min, to study the influence of cutting parameters on cutting force, cutting force empirical model has obtained from least square method.

Abstract: Tool wear plays an important role in cutting process research. It affects the quality of machined surface and cutting parameter to a great extent, such as cutting force, cutting temperature and cutting quiver. In order to predict tool wear in hard cutting process by using FEM method, the character of tool wear during cutting process is presented firstly, and Usui’s tool wear rate model is introduced. Then the FEM model for steady state cutting process using Abaqus is established. FEM model describes the workpiece material characteristic accurately for the process of PCBN tool cutting GCr15 by adoptiving Johnson-Cook constitutive model. Simulation results of steady cutting process offer foundation to simulate tool wear.

Abstract: The polishing robot can serve the polishing work and realize the fully automation for obtaining much higher polishing efficiency and well-proportioned surface quality which attracts many researchers’ attention. In this reviews, the research status of the polishing robot are summarized. Twenty-eight articles which published these years about the polishing robot are introduced in brief. The robot system for complex surfaces polishing, automation of polishing process for a cavity surface, intelligently automated polishing abrasive polishing, the CAD/CAM-based position/force controller for a mold polishing robot and so on are reviewed. More research on an effective gasbag polishing technique based on the novel spinning-inflated-gasbag polishing tool, which can obtain well-proportioned quality surface and high polishing efficiency is a potential one. Investigations of the polishing robot will be helpful for the readers understand the robotic polishing.

Abstract: Tool wear plays an important part during cutting process, and wear loss has a close relationship with cutting condition, which affects machined surface mostly. In order to accomplish tool wear prediction in way of FEM, based on founding of cutting model under steady state, interrelated parameters needed for tool wear prediction, such as cutting temperature, contact pressure and raletive sliding velocity are extracted. By compiling Python subprogram and using Abaqus tool in hard cutting process PCBN tool wear is predicted, which provide foundation for optimizing cutting condition.

Abstract: The influence of different dispersants and suspending agents of CeO2 polishing powder was investigated, including sodium hexametaphosphate, polyethyleneglycoll, polyacrylic acid, anionic polyacrylamide, and their mixtures. The suspension stability of ceria particles in slurries and the pH dependence were examined by the measurement of zeta potential, sedimentation and viscosity, etc. The material removal rate and surface roughness of different slurries for K9 glass polishing were studied. The slurry mixed by three kinds of dispersants can achieved the maximum material removal rate and the minimum surface roughness.

Abstract: Diamond wire saw is the leading technology for use in cutting hard brittle material. Its smaller kerf and faster cutting time make it replacing the conventional slurry technology for those materials. Turned over the traditional router, this paper presents a novel approach that replaces the typical metallic core with a nonmetallic core, for manufacturing of ultraviolet curing resin fixed-abrasive diamond wire saw (DWS). The experiments show that the diamond wire saw made by this manufacturing method can obtain a good performance as well as taking many other advantages.

Abstract: Water-jet guided laser micromachining is the new development orientation of laser machining. This paper set up the numerical model on the action between the water-jet guided laser and the material. By using the software ANSYS, simulated the processing of the water-jet guided laser micromachining. This paper gave the investigation on the machining laws and the distributing of temperature fielding in processing of water-jet guided laser micromachining. And the results of the correlative experiment prove the model aright. The result provided the theoretical foundation for the next research on the water-jet guided laser machining.

Abstract: The stability of powder feeding is important to guarantee the quality of the laser remanufacturing. In order to detect and control the powder flow, a new powder feeding device is designed for laser remanufacturing. Scraper-type conveyer and capacitance sensor are used into the device which is tested by 2Cr13 and H13 powder. The results show that: Using H13 metal powder as medium will get a better effect，and when the changes of powder density are more than 10-1g/min, the device acts better distinguish-ability. The experimental results demonstrate that the system can be used to control the steel base powder feeding.