customized diamond inserts

 

Drilling rocks and/or sawing reinforced concretes are important for modern societies in fields like mining as well as state-of-the-art building.

Diamond tool – that are used for those drilling/sawing applications – are generally made of impregnated diamond inserts. Depending on the application, different geometries, metal bonds, diamond grades and diamond concentrations are used to optimize cutting performances.

It is therefore essential to develop good multilateral information exchanges between manufactures and customers. Those exchanges might – for instance – include investigating and understanding the active wear mechanisms through characterization of worn surfaces as well as of deeper layers in cross-section.

Laboratory testing and wear modeling are also essential for developing tools with improved cutting efficiencies (or Rate of Penetration).

This is with those objectives in mind that we strive to maintain close and discreet partnerships with all our customers.

Partner relationship that include for example :

Applications :

Oil & Gas – High wear resistant impregnated diamond inserts for PDC bits

Oil & Gas – High ROP cutting impregnated diamond inserts for matrix bits

Mining – High ROP cutting impregnated diamond inserts for core bits

Shapes :

Pagode

Mammouth

Standard

Reinforced

Sandwich

Diamond concentrations :

Sandwich Inserts

Sandwich Inserts

Transversal Width Cut

Transversal Width Cut

Encapsuled diamond types :

Capture d’écran 2019-04-01 à 15.39.15
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Laboratory wear tests :

Preliminary wear resiStance tests

Each new composition is preliminary tested :

– in dry and wet conditions

– on SiC and on granite class 5 grinding wheels

Rotational speeds are controlled

Applied pressures range from 1 bar up to 8 bars

Analysis :

Metallography

Worn Segments New Segments
Number of segments 21 21
Analysis
Iron (Fe) 36 % 36 %
Colbalt (Co) 54 % 54 %
Copper-Silver-Titanium 10 % 10 %

Porosity

Opened

Closed

High

Fractography

Fractures around diamonds

Fractures Foot - Matrix

Diamond Clusters

Welding

The segment can be welded onto steel blades by conventional method ( i.e. brazing alloys in strips, in wire, in paste, etc. ) or by laser. A defficient welding can be at the origin of cutting defaults such as deviation cuts, loosed segments, etc. Therefore, it is important to verify the welding.

The welding analysis includes the control of :

– the parallelism of segments,

– the method used,

– the porosity,

– the presence of a foot,

– the composition of the brazing alloys.

Diamonds analysis

The most important part of the cutting tool performance evaluation consists in an analysis of :

– the working surface,

– the aspect of the diamond,

– the diamond concentration,

– the quality and the grit sizes of the diamonds

Working surface :

The working surface analysis covers the general aspect of the surface ( e.g. tails, protusions, glazing surface, etc. ), the diamonds distribution ( e.g. presence of clusters ), the diamond retention ( e.g. number of pull-outs ) and the ratio between :

– pull-outs

– polished crystals

– intact crystals

– crushed crystals

Diamond aspects :

All factors such as cutting parameters, manufacturing parameters, diamonds’ quality, diamonds’ sizes and the concentration have an impact on the diamonds’ behaviour and on the tools’ performances. Indeed, during the cutting operations, the diamonds will be submitted to heavy constraints and will :

– stay intact

– clive or crush

– polish

– leave the matrix

Diamond crushed at the matrix level.

There is no protrusion anymore.

Diamond has lost its cutting properties.

Diamond is crushed but still shows a protusion.

Diamond still keeps its cutting properties.

concentration :

The concentration is measured according to the FEPA norm. By definition, the amout of diamond present in a segment is calculated on a scale in which a concentration of 100 corresponds to 4.4 carats per cm³ or to 25 % in volume.

FEPA
Concentration Carats/cm³ % in volume
C10 0.4 3
C20 0.9 5
C25 1.1 6
C30 1.3 8
C35 1.5 9
C40 1.8 10
C50 2.2 13
C60 2.6 15
C75 3.3 19
C100 4.4 25
quality and grift sizes :

The segments are dissolved into acid bath and the diamonds are cleaned.

Then, the same diamonds are sieved according to FEPA mesh sizes and each class is submitted to a battery of test in order to estimate the qualities of the diamonds.