Papers by Keyword: Free Abrasive

Abstract: In this paper, we point out several problems on fluid mechanics existing in the abrasive flow finishing, and study the dynamic simulations methods in the area. A case study is conducted on the process of free abrasive flow finishing, where we complete the dynamic simulations on the kinematic characteristics by a model of two-phase fluid. It is shown that the theory of two-phase fluid can practically direct the design of polishing machine, and the selection as well as the optimization of parameters for polishing technique.

Abstract: The surface roughness and surface morphology of silicon wafers polished by three different polishing methods were analyzed in this paper. A polishing pad was prepared by means of sol-gel technology as semi-fixed abrasive tool. An electroplated polishing pad was chosen as fixed abrasive tool. And a polishing cloth was chosen as free abrasive tool. The results showed that the surface of silicon wafer polished by the sol-gel polishing pad was superior to the other two. It was easy to get mirror effect with few scratches while the free abrasive and fixed abrasive got lots of scratches on 23silicon wafers. The surface roughness of silicon wafer polished by the sol-gel polishing pad reached 1.41nm measured by atomic force microscope (AFM).

Abstract: In the rapid spray metal tooling, metal film is spray-formed on the substrate and supported under the back, which will act as the working surface of the rapid metal tool finally. So the finishing process for the sprayed metal film is important to the quality and the lifecycle of the rapid metal tool. The finishing of the metal mould is frequently carried out manually, these kinds of operations are iterative, time consuming and require experience. Automation can introduce cost reduction minimizing production times on such manual finishing operations. This paper presents a robotic polishing system with free abrasive for the finishing of the rapid spray metal tool, which is consisted of a six-degree-of-freedom industrial robot manipulator, a high speed electrical polishing spindle and a numerical swivel table. Soft polishing pad and free abrasive are also selected for the robotic polishing system. The path planning is so important to the robotic polishing system that a partition & flexible path mapping method basing on UG CAM is developed to generate the uniform robotic polishing path on the complex mould surface. UG/Open GRIP programming module is used to generate the driving paths with different path intervals on the predesigned plane for each partitioned part. When the driving paths are projected to the mould curved surface, the uniform polishing paths with NC code can be generated by the multi-axis CAM module of the UG. And the path with NC code can then be transformed to the robotic polishing path. According to the elastic deformation and the abrasion of the soft polishing tool, the robotic polishing path should be adjusted to keep the smooth polishing process by offsetting the pre-compressed value and the abrasive compensation value along the polishing axis direction. Technical parameters of the robotic polishing process are also optimized through the experiments. Finally, the rapid metal punch mould is finished to test the robotic polishing system.