Mechanical Properties

Mechanical Properties

At Engis we measure the Mechanical Strength of both diamond or CBN crystals, which is the ability resist fracturing under static or dynamic (impact) loading. This is the most important property of the crystal and mirrors all other properties (size, shape and level of crystal growth defects). Crystal’s strength is critical to you when choosing a product as certain applications, such as working with stones and construction materials, which will require a diamond that will stay strong, not fracturing and ultimately losing its sharpness.

Technique and Equipment

• Mechanical strength of diamond/CBN crystals is measured through crushing a sample consisting of a large number of crystals sharing similar size, shape and level of crystal growth defects under controlled loading and shear
• Our in-house developed technique uses a combination of compressive and shear forces to crush micron sized diamond powder
• Particle Size Distribution (PSD) is measured before and after crushing
• The Crushing Strength Index is calculated based on that portion of PSD which remains true to size after crushing

We also analyze Micro-Fracturing Characteristics which is the ability of diamond/CBN particles to fracture under severe mechanical stresses and develop new fresh cutting edges and points (a so-called self-sharpening mechanism).

Technique and Equipment

We utilize the appropriate particle size analyzers and analysis techniques to analyze the “crushed” diamond/CBN powders in micron and submicron size range, from which the differences in the amount and size of “fine chips” generated during crushing can be revealed.

The fine particle analysis shows that the RA and MA powders exhibit different micro-fracturing characteristics with RA diamond powder generating more fine particles less than 1 micron when compared to the MA4 diamond powders.

Micron Particle Sizing & Sub-Micron Fine Particle Analysis