Jan

What Process Should Do for PCD Edge Grinding?

1. Selection of PCD Tool Grinding Machine

pcd tool grinding machine

Due to the high hardness and wear resistance of PCD tools, it is difficult for general machine tools to meet the precision requirements of its edge grinding. According to the characteristics of PCD tools and the necessary conditions of mechanical insert grinding, we suggest you use Coborn RG9, EWAG RS15 as well as MT-188 and MT-198 super abrasive tool grinders. These machine tools are the most advanced super hard tool grinders in the world with the following characteristics:

1） High rigidity and good stability

2）Grinding spindle can adjust speed

3）Grinding pressure is adjustable and stable, and can swing back and forth, swing amplitude and frequency are adjustable

4）Equipped with high precision optical projector and rotary table, the whole process of positioning, grinding and measurement can be completed by clamping at a time

5）Equipped with digital display device, dimension accuracy is controllable

2. Selection of Diamond Grinding Wheel

PCD grinding wheel

The mechanical cutting edge grinding of PCD tools mainly relies on the tribochemical reaction and surface fracture of diamond grinding wheel to remove the excess material. The particle size(grit), concentration and binder(bond) of diamond grinding wheel have a great influence on the quality and efficiency of PCD tool cutting edge grinding. Therefore, the correct selection of grinding wheel is very important. For the grinding wheel produced by MORESUPERHARD, the diamond grains are strictly screened and arranged in an orderly and uniform manner. The grinding removal rate per minute is 20 ~ 30 times that of the ordinary diamond grinding wheel. The experience shows that the grinding wheel with larger grain size should be selected as far as possible on the premise of satisfying the processing quality requirements. The recommended diamond grinding granularity is 22um for rough grinding. Semi-fine grinding grain 15um; Fine grinding particle size 9um. The polishing effect of our super fine grinding wheel 4000#-6000# is also particularly remarkable.

grinding PCD reamers

3. Balance of Diamond Grinding Wheel

After selecting the grinding wheel, the grinding wheel shall be balanced. Firstly, the grinding wheel balancer is placed on the mirror table for calibration. By adjusting the three balance nuts at the bottom of the balancer, the balance bubble in the balancer is placed in the center. Then, slide the grinding wheel into the adjusting rod of the grinding wheel, adjust the three balance screws on the side of the grinding wheel so that they are evenly distributed (clamping 63 Angle to each other is about 120), until the balance bubble in the balancing instrument is located in the center again, and the grinding wheel is balanced.

4. Clamping and adjust the PCD tool between the rotary center and the optical center

grinding

First, the center of the cross table and the center of the optical projector to coincide in the middle, through the adjustment of the optical projector set screw, so that the highest point of the knife point and the outside of the projector in a large arc in 270°, 0°, 90° tangent; Then, according to the drawing requirements, adjust the PCD tool clamping through a cross table to the reference line of the optical projector, which is the cutting edge grinding position. In order to ensure the machining accuracy of PCD tools, all grinding dimensions should be completed in one clamping. All wear should be removed when grinding PCD tools.

5. Selection of Wheel Swing

grinding PCD inserts 4

In order to make full use of the grinding ability of the grinding wheel and prevent the appearance of groove, the swing amplitude of the grinding wheel should be reasonably selected according to the PCD cutter size.

6. Determine Grinding Speed, Frequency and other parameters

Through a large number of tests, it is determined that the speed of PCD cutter for cutting edge grinding is 2300 ~ 2800r/min (150mm grinding wheel), and the grinding wheel is rotating forward. Generally, the higher the cutting frequency is, the higher the grinding rate is. The cutting frequency of PCD cutter is selected for 60 times/min. Other parameters: water – based coolant concentration 4%, grinding pressure 2.5Bar(approx. 167N).

7. Cleaning of Diamond Grinding Wheel

After grinding for a period of time, the gap between the grinding grains will be filled with the grinding chips, resulting in the grinding surface becoming blunt or even blocked, and the processing efficiency will be reduced (at this time, the grinding wheel will often squeal during grinding). In order to maintain the cutting ability of the grinding wheel, it is necessary to clean the cutting surface of the grinding wheel frequently. The method is to press the silicon carbide (SIC) grindstone on the grinding surface of the grinding wheel and rotate grinding, or online cleaning can be selected. My-tech series grinders can realize online cleaning and dressing functions. Dressing is equipped with ceramic diamond dressing wheels produced by MORESUPERHARD, whose efficiency is several times that of ordinary silicon carbide grinding wheels. In addition, when the grinding wheel is blocked, we also have customers use ultrasonic cleaning, the effect is also very good oh, if you have an ultrasonic machine, might have a try.

coborn pg9 grinding machine

8. Treatment of PCD tools before and after edge grinding

Before grinding a PCD tool, observe whether there are aluminum scraps on the front and rear knife surfaces. If there are, wipe them with diamond whetstone. After grinding, the front end face is ground with diamond grinding paste. After rough grinding, semi-fine grinding, fine grinding, grinding treatment of PCD tools can really meet the use requirements.

9. Detection of PCD Tool

detection of PCD tools

After edge grinding, the PCD cutter’s dimension accuracy and edge straightness can be directly detected on the projector of the machine tool. No obvious defects such as uneven or zigzag shape are allowed. The flatness of the cutting edge can also be examined under 100 times microscope.

Moresuperhard Products Co.,Ltd has one series of solution on PCD&CBN tools

(such as tool blanks, tool inserts, milling tools, reamers,and honing tools),from the raw PCD/PCBN blanks, the PCD/CBN grinding wheel, the PCD/CBN tools grinding machine, laser cutting machine, polishing and lapping machine & wheels, chamfer machine &wheels,and the brazing machine include the high frequency & the vacuum brazing machine for PCD/PCBN tools. More details you can visit our website www.pcdgrinding.cn.

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