Diamond Grinding Discs Aka-Piatto & Aka-Piatto +

Grinding is the first “real” preparation step. Cutting and mounting are not always necessary, but for a successful metallographic sample preparation a correct sequence of grinding and polishing steps is a must.
The first step is usually a plane grinding step, either to level all samples in a sample holder, and/or to remove the initial deformation from the sample surface. Depending on the sample size and the depth of deformation, relatively coarse abrasives are used to obtain short grinding times.
A major goal in sample preparation today is to receive a satisfactory result in the shortest possible time at the lowest possible cost. Therefore every step must be considered carefully, also in relation to the following step and the required finish. It does not make sense to have a very fast plane grinding step if that produces a lot of deformation that will take a very long time to remove in the following step(s).
The plane grinding step must be selected carefully, as it is crucial for the following preparation steps. It must be fast and at the same time produce samples with a very shallow deformation depth. And the better the planeness of the samples after plane grinding, the faster the following step can be carried out.

Plane Grinding
For materials with a hardness higher than 150 HV, the best possible choice is the Aka-Piatto. Aka-Piatto is a multi-layer diamond grinding disc that can replace at least 100 - 200 pieces of SiC Paper. It has a consistently high removal rate and will provide absolutely plane samples with perfect edge retention.
For plane grinding of soft materials with hardness below 150 HV or very ductile materials with a higher hardness grinding paper can still be the correct choice, but harder materials will greatly benefit from the Aka-Piatto. Depending on the size and the hardness of the samples, Aka-Piatto in grit sizes P80 – P220 is used for plane grinding.
Usually a single plane grinding step is sufficient when grinding with Aka-Piatto. The absolutely plane samples make it possible to speed up the following fine grinding step.
The table below shows the correct application areas for the different grinding consumables.

Fine Grinding
After plane grinding, traditionally several fine grinding steps in successively finer grit sizes have been used to make the samples ready for polishing.
Also here, new technology has made it possible to speed up preparation and reduce fine grinding to one single step.
Aka-Allegran and Aka-Largan apply a unique system for material removal. Integrated abrasive is released during preparation while abrasive in the form of diamond suspension or diamond spray is applied. The result is high removal, perfect planeness and an exceptional long lifetime.
Aka-Largan and Aka-Allegran replace a number of grinding steps, typically P320 - P1200 with one single fine grinding step. With a constant removal rate these discs are also ideal for automatic preparation systems that rely on con- stant, reproducible settings on every step.
Alternatively, Aka-Piatto can be used in the more traditional way where several grinding steps are carried out successively. As Aka-Piatto is used with water only, cleaning is easier than with Aka-Allegran or Aka-Largan, and not even necessary in-between preparation steps.
For very soft and/or ductile materials it can still be necessary to use traditional grinding paper

Aka-Piatto
Unique to Aka-Piatto is the colour-coded binder and a wear compensating surface design increasing the planeness of the samples and the lifetime of the Aka-Piatto discs.
3 small tabs make it easy to exchange the Aka-Piatto discs.
Depending on the sample size and machine set-up at least 150 pcs. of grinding paper can be substituted by one Aka-Piatto disc.
The Aka-Piatto discs have to be opened with a dressing stick before the first use, and depending on the material being prepared, dressed once in a while during use.
We recommend using the dressing stick AP9885 to be found in the Accessories section.

Aka-Piatto+
Aka-Piatto+ is a series of discs with an even higher diamond concentration than Aka-Piatto.
The effect of Aka-Piatto+ is an improved lifetime and finer surface finish on brittle samples like ceramics and cermets due to the lower specific pressure.
Used on metals it results in a finer finish and up to 100% longer lifetime com- pared to regular Aka-Piatto discs.
Aka-Piatto+ shares all the same features as Aka-Piatto, like colour-coding, the wear compensating design and the 3 small tabs for easy exchange.
The Aka-Piatto+ discs have to be opened with a dressing stick before the first use, and depending on the material being prepared, dressed once in a while during use.
We recommend using the dressing stick AP9885 to be found in the Accessories section.