PCD Cutting Tool Grinding Process

Selection of PCD cutting tool grinding machine

Due to the high hardness and wear resistance of PCD cutting tools, the grinding requirements are high, and it is difficult for general machine tools to meet the grinding accuracy requirements. It has the following characteristics:

• The overall rigidity of the machine tool is high and the stability is good;

• The grinding spindle can achieve stepless speed regulation (1000-8000rpm);

• The grinding pressure can be adjusted (0-400N) and has good stability, and can be reciprocated. The swing amplitude (0-70mm) and frequency (30-60 times/min) can be adjusted;

• Equipped with high-precision optical projector and rotary worktable, one clamping can complete the positioning, grinding and measuring process;

• Equipped with digital display device, the size accuracy can reach 0.001mm.

Selection of PCD cutting tool grinding wheel

The mechanical grinding of PCD cutting tools mainly relies on the frictional chemical reaction and surface fracture of diamond grinding wheel to remove excess material. The particle size, concentration and binder of diamond grinding wheel have a great impact on the quality and efficiency of PCD cutting tool grinding. Therefore, it is very important to choose the right grinding wheel.

Experience has shown that, under the premise of meeting the processing quality requirements, grinding wheels with larger particle size should be used as much as possible. The diamond grinding grain size we use is: rough grinding grain size 22um; semi-fine grinding grain size 15um; fine grinding grain size 9um.

Balancing of PCD cutting tool grinding wheel

After selecting the grinding wheel, it needs to be balanced. First, place the wheel balancer on the mirror platform for calibration. Adjust the three balance nuts at the bottom of the balancer to make the balance bubble inside the balancer in the center. Then slide the grinding wheel into the wheel adjusting rod, and adjust the three balance screws on the side of the grinding wheel to make it evenly distributed (angled at 63 degrees and approximately 120 degrees apart from each other). When the balance bubble inside the balancer is in the center again, the grinding wheel is balanced.

Mounting and adjusting PCD cutting tools with rotary center and optical center

First, the rotary center of the cross worktable should coincide with the center of the optical projector. By adjusting the fixing screws of the optical projector, the highest point of the blade edge should be tangent to a certain large arc on the outside of the projector at 270 °, 0 °, and 90 ° respectively. Then, according to the requirements of the drawing, adjust the mounted PCD cutting tool to the reference line of the optical projector through the cross worktable, which is the grinding position.

To ensure the processing precision of PCD cutting tools, all grinding dimensions should be completed in one clamp, and all wear should be cut off when grinding PCD cutting tools.

Selection of grinding wheel swing range for PCD cutting tools

Due to the high cost of diamond grinding wheel and to fully utilize its grinding ability and prevent grooves, the swing range of the grinding wheel should be selected reasonably according to the size of PCD cutting tools.

Determination of grinding speed, frequency and other parameters for PCD cutting tools

Through a large number of tests, the grinding speed of PCD cutting tools is determined to be 2300-2500r/min (150mm grinding wheel) and the grinding wheel rotates forward. Generally speaking, the higher the grinding frequency is, the greater the grinding removal rate is. The grinding frequency of PCD cutting tools is selected as 60 times/min. Other parameters are: water-based coolant concentration of 4%, grinding pressure of 2.5Bar (about 167N).

Cleaning of PCD cutting tool grinding wheel

After a period of grinding with the grinding wheel, the gaps between the abrasive grains will be filled with debris, which will cause the grinding surface to become dull and the processing efficiency to decrease (at this time, the grinding wheel often emits a squeaking or screaming sound). In order to maintain the cutting ability of the grinding wheel, it is necessary to regularly clean the cutting surface of the grinding wheel by rotating and grinding with silicon carbide (SIC) grinding stone.

Treatment of PCD cutting tool blade before and after grinding

Before grinding PCD cutting tools, check whether there is aluminum debris on the front and rear cutting surfaces. If so, remove it with a diamond oilstone. After grinding, use diamond polishing paste to grind the front end face. The PCD cutting tool processed by rough grinding, semi-fine grinding, fine grinding and grinding can truly meet the requirements of use.

Detection of PCD cutting tools

After grinding, the size accuracy and straightness of the blade edge of PCD cutting tools can be directly detected on the projector of the machine tool. Obvious defects such as unevenness or serration are not allowed. The straightness of the blade edge can also be checked under a microscope of 100 times or more. Our high-quality diamond powders are ideal for the grinding and polishing process of PCD cutting tools, ensuring optimal performance. As leading PCBN blanks and resin bond suppliers, we are committed to providing products that enhance the accuracy and efficiency of your tool grinding processes.