Orderly-micro-grooved pcd grinding wheel for positive rake angle processing and method for making same

Abstract

Disclosed are an orderly-micro-grooved PCD grinding wheel for positive rake angle processing and a preparation method thereof. A PCD film is deposited on the outer circumferential surface of a wheel hub, and a plurality of microgrooves with high depth-width ratio and micro-grinding units with positive rake angles are orderly provided on the outer circumferential surface of the entire PCD film. The method includes: depositing the PCD film on the outer circumferential surface of the wheel hub by a HFCVD technique; and manufacturing a plurality of microgrooves with a high depth-width ratio (circumferential width: dozens of micrometers; depth: hundreds of micrometers) and an axial length that is equal to the thickness of the grinding wheel and a plurality of micro-grinding units with positive rake angles on the outer circumferential surface of the entire PCD film by water-jet guided laser technique, where the micro-grinding units and the microgrooves are orderly arranged.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of International Patent Application PCT / CN2019 / 090698, filed on Jun. 11, 2019, which claims the benefit of priority from Chinese Patent Application No. 201810608183.3, filed on Jun. 13, 2018. The content of the aforementioned application, including any intervening amendments thereto, is incorporated herein by reference.TECHNICAL FIELD[0002]This application relates to a grinding wheel and a preparation method thereof, and more specifically to an orderly-micro-grooved PCD grinding wheel for positive rake angle processing and a method for making the same.BACKGROUND OF THE INVENTION[0003]Grinding has been widely applied in the precision machining due to the characteristics of high processing precision and good surface quality. However, in the traditional grinding process, abrasive grains are irregularly arranged on the working surface of the grinding wheel, and vary in geometrical shape and size, so that the...

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Benefits of technology

[0028](4) This application significantly extends the service life of the grinding wheel.

[0029]The PCD film on the outer circumferential surface of the grinding wheel prepared by a HFCVD technique is operated as a whole, and each micro-grinding unit is part thereof, which greatly improves the holding force of the grinding wheel on the micro-grinding units, preventing the micro-grinding units from singly falling off due to excessive or concentrated grinding force and significantly improving the service life of the grinding wheel.

[0030](5) This application increases the number of effective cutting edges and alleviates the periodic vibration during the grinding.

[0031]The microgrooves obtained by the water-jet guided laser technique have a circumferential width of only 20 μm, and the micro-grinding units have a circumferential spacing of only 100 μm, so that the number of micro-grinding units involved in grinding per unit area is significantly increased, greatly alleviating the periodic vibration during the grinding. The micro-grinding units prepared by the method have the characteristics of high protrusion and good consistency, so that the cutting edge of each micro-grinding unit can participate in the grinding, which greatly increases the number of effective cutting edges in the grinding process and reduces the cutting depth of the single cutting edge, effectively improving the grinding precision and efficiency.

[0032](6) This application has simple preparation process and low cost.

[0033]The size and shape of the micro-grinding units on the outer circumferential surface of the grinding wheel both have a good periodicity. Therefore, in the preparation process, the relative motion relationship between the Laser-Microjet device and the grinding wheel can be controlled by the numerical control technology, which greatly reduces the difficulty in preparation of the grinding wheel and lowers the cost.

Problems solved by technology

However, in the traditional grinding process, abrasive grains are irregularly arranged on the working surface of the grinding wheel, and vary in geometrical shape and size, so that the abrasive grains often cut the surface of the workpiece in a large negative rake angle during the grinding process, which will increase the grinding force ratio, accelerate the conversion of grinding energy into heat and raise the grinding temperature, affecting the surface quality and grinding efficiency.

In addition, the grinding wheel also has disadvantages of small chip space and low protrusion of abrasive grains, and the grains are easy to fall off, which may easily cause a blockage at the grinding wheel and produce a local high temperature to damage the workpiece surface, and reduce the service life of the grinding wheel.

However, the single grinding unit is still operated at a zero rake angle during the grinding process, so that the grinding efficiency and the surface quality cannot be further improved.

Meanwhile, the circumferential spacing of the orderly arranged grinding units in the grinding process reaches 1 mm, which will result in a typical intermittent grinding, and the generated periodic vibrations by the grinding process may also affect the integrity of the processed surface.

However, in the process of processing large-sized diamond abrasive grains by laser, the high laser ablation temperature will inevitably cause partial graphitization on the diamond abrasive grains, affecting the positive-rake angle cutting of the abrasive grains for the workpiece surface and reducing the surface quality of the processed surface.

At the same time, the single large-sized diamond abrasive grain may fall off if it is subjected to excessive or concentrated force, which may affect the grinding efficiency and even reduce the service life of the grinding wheel.

However, since the fiber has a cross-sectional size of 0.8 mm×0.8 mm and the number of fibers per square centimeter on the surface of the tool is only 14.26, the single fiber may have a large cutting depth, making it difficult to ensure the processing precision.

Moreover, a rupture will occur if a single fiber is subjected to an excessive or concentrated force, which may affect the service life of the grinding wheel.

There are also great difficulties in the process that all the fibers are inserted into the small holes one by one and consolidated.

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