Quality Control and Testing Procedures

LANDS Superabrasives performs various standard tests in order to assure and maintain a consistent standard in its product line. In order to guarantee optimum Quality Control in producing consistent materials throughout the line,   LANDS Superabrasives has developed a standard testing procedure that involves continuous monitoring of the vital variables. This testing procedure is one of the cornerstones of our Quality Control Program.

In the following paragraphs LANDS Superabrasives presents some of the standard tests used in the Quality Control Maintenance of the product line.

Description of Tests and Testing Procedures

Friability Test. Toughness Index.

Test Objective: The main purpose of this test is to determine the relative strength of the diamond particles. The core of this test is to determine the particle size after the material is subjected to controlled crushing.

Test Procedure: First the diamond is sieved and measured. The sample is then subjected to controlled crushing in a mill using hardened steel balls. The vibration, movement and amplitude of this process is fully controlled. After a defined time period, the diamond is collected and measured again. There is a direct correlation between the spread in residue sizes after crushing and crystal strength. In general, the coarser and larger the residue, the stronger the original crystal; the finer and smaller the residue crystals, the weaker the original crystal

Result: A Toughness Index is generated by using a formula which relates the various factors of time, crushing procedure and final particle size.

Friability Test after Thermal Impact. Thermal Toughness Index.

Test Objective: To determine the thermal stability of diamond products.

Test Procedure: This test is the same as described above, however the diamond is first heated to 1125 C. in a controlled non-oxygen atmosphere.

Heating may cause the crystal to break up or to damage the surface, edges and the faces. Strong crystals will yield lower percentages of fine sizes compared to weaker crystals, which yield relatively higher percentages of fine sizes.

Result: A Thermal Toughness Index is generated by using a formula which relates the various factors of time, crushing procedures and final particle size. The higher the value of the TTI, the stronger the crystal.

Test Objective: To determine the density of the material

Test Procedure: The bulk density is determined by the weighing the amount of material required to fill a predetermined volume. (Similar to 1 kg of water fills exactly 1 Liter.)

Result: Bulk density provides a relationship between the average shape and smoothness of the crystals and specific weights.

Test Objective: To determine the size of diamond particles.

Test Procedure: All Mesh powders are sieved according to the latest ASTM / FEPA standard sieving procedures using electroformed sieves (ANSI B74.16, FEPA and ISO 6106)

Both "Mesh" and "Micron" sizes are obtained by applying consistent and stringent procedures to sieving and sieving techniques.

Result: Consistently graded products, with uniform distribution.

LANDS issues histograms upon request, showing the distribution of particles in the powders, measuring median and Cumulative Distributions.

Test Objective: To determine the color of diamond particles to insure color consistency of diamond specimens.

Test Procedure: a light diffracto-meter determines the exact color of all diamond specimen.

Result: By setting color range standards, LANDS guarantees color consistency for each and every product. If the specimens are not within the range of tolerances, batches are rejected.

Test Objective: To determine the shape of diamond crystals.

Test Procedure: Diamond crystals are tabled on vibrating tables, which result in the separation of the material into various batches of crystals having similar shape. Each shape is assigned a relative index value that indicates the overall particle shape of the sample.

Result: A range of classes of products, wherein each class of crystals are graded so that a uniform and consistent product is guaranteed.

Test Objective: To determine various visual appearances.

Test Procedure: The diamond is checked under a stereo microscope with different illuminations (light intensities). Shape, structure, color and degree of inclusions are examined.

In addition to the above tests, LANDS Superabrasives administers a variety of other proprietary tests on the aspects of diamond properties such as Impact Resistance, Fatigue Resistance and Crystal purity.