Another trend in the development of PDC drill bits is the study of new high performance
PDC cutting teeth. The first is still to improve the cutting elements (polycrystalline
Diamond composite sheet) wear resistance, mechanical properties, work
Artistic performance and cutting performance. For many years, the gold of PDC cutting teeth
The thickness of the stone is limited to 0.6mm (0.025 inches), which is because
The researchers established the residual stress and diamond thickness of the cutting teeth.
system. Residues in the PDC cutting teeth during the pressing process
Stress, the size of which increases with the thickness of the diamond layer.
Stress causes cracking, spalling, delamination of the diamond layer, which reduces
The life of the PDC cutting teeth and the efficiency of the drill bit. To this end, polycrystalline gold
The rock stone composite sheet shows the following development trend.
1. Improve the performance of the composite
In order to improve the performance of the composite sheet,
First, improve workability
Energy and life index (increased wear ratio, surface roughness, impact resistance
Strike), the second is to improve the process performance indicators (increasing thermal stability).
Under this guiding ideology, many high wear ratios, high heat resistance,
High impact resistant composite sheet, polished sheet, mirror sheet, etc.
2. Change the structure of the composite sheet
Change the structure of the composite sheet to improve the diamond layer and hard bond
Adhesion ability of gold matrix, impact resistance, machinability during work
Ability to adapt to the formation. Appeared under this guiding ideology
Many new structural composite sheets,
One type is a thickened composite sheet, such as gold.
Rigid stone layer edge thickening type, overall thickening type, hard alloy matrix plus
Thick type ;
One type is a non-planar interface type composite sheet, such as radiation
Groove, annular groove, claw (rectangle, trapezoid, wavy) tooth
Wait . Non-planar interface technology can reduce the stress of PDC cutting teeth
Gradient and away from the edge of the diamond. This technique
Allows for increased cutting teeth without creating the aforementioned stress relationships
The thickness of the diamond layer is such that it reaches 2Inn1 (0.08 inch)
Or 2.54ITlln (0.1 inches).
3. Improve the shape of the composite sheet
Improve the shape of the composite sheet and develop a heterogeneous composite
Pieces, such as wedge teeth, rectangular teeth, ball head teeth, etc. There are still many new types
Cutting element hybrid composite, formerly Soviet Slavutz
and Tavisa (TBEa bI) as representatives,
There are also pregnant teeth (preceding natural diamonds in the cemented carbide matrix,
Single crystal, polycrystalline) and mosaic cutting teeth.