Advanced Materials Research Vols. 102-104

Abstract: Two kinds of Cemented carbide tools were used to turn Iron-based superalloy GH2132 at 80m/min-210 m/min under dry cutting condition. Infrared thermometer was used to measure cutting temperature, Tool wear was observed by SEM, and oxygen element distribution of tool surface was analyzed by EDS. Adhesive wear oxidation wear were the main wear mechanisms of the coated cemented carbide tool, Adhesive wear, abrasive were the main wear mechanisms of the carbide tool. Oxidation wear occurs above a certain temperature about 430°C, the higher the temperature the more serious the oxidation wear is. The results might be helpful to guiding the design and selection of tool materials and control of tool wear in high speed machining processes.

Abstract: A nanometer precision location stage for micro-EDM was designed, which was built by the using of ultrasonic motor as driver unit. The stage precision test was done then. The results showed that the stage worked well and reached high precision. The research provided a new solution about the design of precision location stages.

Abstract: The paper based on the domestic research result and foreign research result on error compensation, aimed at the geometric feature of a three dimensions micro-EDM stage. By the coordinate matrix transformation method, we have developed the three dimension kinematics synthesis error mathematical model. Then the micro-EDM stage error was compensated. The error model for the stage is simple and error compensation is easy.

Abstract: The design of NC reconstruction of a machine tool and the parameters conversion are elaborated by means of an example of sphere grinding using a common grinding machine which has been reconstructed by special NC technologies. The grinding of a large size sphere is realized by using the linear instruction. The variable speed rotary grinding of a large size sphere is realized by using the arc instruction. The instantaneous compensation of the grinding wheel is realized by using the screw instruction. The function and application scope of NC technology are expanded because of variable speed rotary motion and instantaneous compensation of the grinding wheel.

Abstract: The development of surface high-speed machining has put forward higher demands for uniform cutting load and smooth cutting tool path. Most current tool-path planning methods are based on constant scallop height, but they have the disadvantage of path point redundancy during the path discretization process. To overcome the problem, a tool path generation method of equal approximation error in each step for free-form surface is presented based on geodesic principle and curvature judgment. In this method, the NURBS curve is employed to realize smooth transition for adjacent two tool paths in high-speed machining. A certain angle of inclination of flat-end milling cutter during multi-axis machining improves the machining efficiency. Because of the advantage of this machining condition, the cutter location point generation algorithm during the machining condition is given by the method. The method is verified and simulated by C++. Experiment results proved that it can obtain uniform cutting load and continuous smooth cutting tool path during surface high-speed machining by the proposed method.

Abstract: The scaffolds of bone tissue engineering (BTE) are designed with complex interconnected pores for providing mechanical support, cell attachment and nutrition delivery, and can be directly fabricated via rapid prototyping (RP). Based on reviews on amount of papers, fundamental of BTE, including research procedure and biomaterials for scaffold are presented. And various RP methods for scaffold fabrication, including selective laser sintering (SLS), fused deposition modeling (FDM), 3 dimension printing (3DP), are introduced. The conclusions including existing problems and future researches about BTE scaffold fabrication are given at the end.

Abstract: This paper analyses the kinetic trajectory of abrasives both in initiative driving mode and passive driving mode, and the uniformity of lapping trajectory of the two opposite drive modes is discussed, respectively. The imperative relation between the kinematic trajectory and the uniformity is researched in this paper, as well as the simulation of the lapping trajectory.

Abstract: The machining method and characteristic of the ultrasonic extrusion-rolling machining was introduced in the paper. According to the machining characteristic, the kinematic analysis of the machining mechanism and surface anamorphic was analyzed too. And then the correlative theory of tribology was adopted to discuss the relation between surface anamorphic quantity and the technological parameter. The theory foundation was afforded for the choice of technological parameter.

Abstract: This paper presents the parameters optimization by TRIZ theory in the precision lapping of sapphire in order to realize the high efficiency and low damaged lapping. The TRIZ theory was used to optimize processing parameters of sapphire precision lapping based on much experimental data of lapping, then the conflict matrix of internal contradictions was set up and the optimization parameters was obtained. The result of experiment indicated that the face quality of sapphire was improved greatly after optimized by TRIZ. There was a conclusion that TRIZ theory can be used to optimize the processing parameters of sapphire precision lapping which is important to enrich the processing theory of sapphire.

Abstract: To improve the quality and efficiency of the finish, industrial robots are used to polish the workpiece cavities with complex shapes. This paper presents key technologies of robotic polishing system including path generation, tool orientation control and G-code converting. Robot path data is generated automatically from the NC data, and tool posture angle is superadded to the robotic polishing path according to the requirement of the robotic polishing technology. Specialized software is developed to automatically generate a program, which includes the path data and tool posture angle, and this program is uploaded to the robot controller for the die polishing process.