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What is an impregnated diamond core drilling bit?

Impregnated diamond coring bits are tools widely used in exploratory drilling. They feature a high drilling speed and a quality drill core easily moved. There are many impregnated tools applicable in various drilling conditions and moreover which comply with the international standards. Impregnated tooling core bits can be used in drilling rocks of any type.

Impregnated diamond core bits have emerged to be the most commonly used in mineral exploration industry. There are many benefits related to them as compared to the bits manufactured with other cutting media. Some of these benefits include:
• The coring bits have a wide range of applications
• Simple crown geometry makes them less prone to in-hole damages than the other types of bits made with other types of crown media. Moreover, they are more tolerant to changes or banded geological formations.
• They feature sintered matrix which result to better overall bit life than the other bits produced with multi-layered cutter arrangements. They are more suitable when drilling hard, consolidated and non-abrasive formations.

The basic construction of the diamond core bits features sintered powdered metal crown-fused to a steel tool shank or body. The powdered metal crown consists of two layers. The matrix layer cuts the rock while the backing layer connects the matrix layer to the steel body and it also serves to support the gauge diameter protection material.

The cutting media used in diamond impregnated core bits is premium high grade quality synthetic diamond powders. It has a distinct advantage over the other natural mined industrial diamond used to surface-set diamond coring bits. It is an engineered material which bears a measurable and controllable physical properties and particularly in the areas with crystal geometry and crystal friability.

The matrix layer of the bit crown contains a uniform distribution of diamond crystals embedded in powdered metal bond. The grit size and synthetic diamond crystals concentrations and the relative hardness of metal bonds materials which they are suspended are usually functions of the matrix type designation.

There is wide range of impregnated diamond matrix layer metal bonds, which also range from the hard, abrasion resistant types to the soft ductile parts. Generally, you can use a hard abrasion resistant matrix to drill a soft abrasive and unconsolidated formation and use a soft ductile matrix in drilling an extremely hard, non abrasive and unconsolidated formation. The idea behind this is to match the bit matrix hardness to formation hardness to allow the metal bond matrix layer to erode in controlled rate during a normal drilling operation. The matrix layer metal bond controlled erosion continually exposes new layers of the sharp synthetic diamonds until the bit crown matrix layer wears out completely.

The backing layer does not feature a diamond distribute throughout its volume contrary to what is witnessed with a matrix layer. Its backing layer also consists of a powered metal bond material, which is usually a bond type with wear resistance properties. In general, the exposed inside and outside gauge diameter surfaces are made with a natural mined kicker grade diamond and a tungsten carbide wear pads combination. The materials assist in critical gauge diameter maintenance throughout the bit’s life. Optional settings are also available but they have the natural mined kicker grade diamond replaced with synthetic materials. They are designed for use in drilling projects with objectionable diamond crystals contamination.