Research Of Brazed Diamond Grinding Wheels Using Laser Beam

Because of the unique advantage, brazing super-abrasive tool is a focus in the field of super-abrasive tool. Presently, there are two preparation methods for high-temperature brazing diamond tool: vacuum furnace brazing and induction brazing. The different diamond tools have their unique advantages and working field. Additionally, they also have some inevitably disadvantageous. From a long-run viewpoint, the brazed tools have an improving and developing space. Based on the former research on the fabrication technology of the diamond tools, including vacuum furnace brazing and induction brazing, the way to develop diamond tools by laser brazing was put forward in this investigation. It could provide a new means to braze diamond grits.The main contents in this paper are as follows:(1)The method of standard thermocouple is finally confirmed for measuring the temperature of laser brazing, by analyzing principium and variety of thermocouple measuring. The temperature of laser brazing is measured using the method of orthogonal test. The technical parameters for laser brazing test are acquired using optimizing test. It is very important to optimize the working parameters in the laser brazing.(2)The amelioration of laser brazing protector is completed, Then, brazing diamond grits to 0.45%C steel substrate with Ni-Cr-B-Si filler alloy was carried out by using laser beam in an argon atmosphere. All the results indicate that high bonding strength between diamond grains and the steel substrate has been realized successfully when the linear density of the laser power is between 244～256J/mm2. The new-formed reaction products and the interfacial microstructure under the different conditions have been detected by three-dimensional stereomicroscope, scanning electron microscope, energy dispersion spectrometer, and X-ray diffraction. The results show that, during brazing, Cr atoms segregated to the interface area and reacted with C ones to form carbide Cr3C2, which distributed as flake around the diamond. (3)In this work, the diamond grinding wheels with segment structure were firstly prepared successfully by laser brazing. Meanwhile, the machining performance of the brazed diamond tools was evaluated. The result shows that there ie a main type of laser brazing diamond grain damage, viz. whole, wear-away, edge-fractured, fractured. None of the grits in the connecting layer was pulled out from the tools. The diamond shapes greatly make grinding forces vary and their variations enhance the transform of diamond shapes. The results obtained in this paper provide a reference for consummating the manufacture of laser brazed diamond tools.