Since 2019, Kamado Argentino has had a strategic alliance with CETMIC in Argentina for the development of exclusive raw materials and for quality control of each batch manufactured.

Starting from 2021, CETMIC designed an exclusive quality control protocol for Kamado Argentino.

The evaluation of the behavior of the ceramics that compose the Kamado are subjected to the following study and analysis of the following properties:

1. SENSORY INSPECTION

Visual and tactile analysis allows for a general statistical perception level of the ceramics to be studied without the aid of measuring instruments. This study aims to obtain macroscopic visual and tactile parameters of the KAMADO-type furnace.

2. THERMAL BEHAVIOR

Thermoanalytical techniques are used to qualitatively and/or quantitatively evaluate the behavior of ceramic pastes as a function of temperature. Information is obtained to monitor the firing process, determine the thermal stability of the materials, quantify loss by calcination, and complete phase identification (Conconi, 2010).

2.1- DIFFERENTIAL THERMAL ANALYSIS

Differential thermal analysis (DTA) DIN 51004/007 is a technique that measures heat flow in a material as a function of temperature or time in a controlled environment. It records the temperature difference between the sample and a reference material. A thermally inert substance that does not undergo changes in the temperature range of the experiment is designated as the reference substance. The measurement is important when the substance under study undergoes chemical and/or physical transformations with heat exchange during thermal treatment. When a reaction occurs at a certain temperature that releases or absorbs energy, the sample will heat up or cool down relative to the inert substance (reference material). This temperature difference is expressed in endothermic or exothermic reactions. In sintered ceramics, this measurement is useful for evaluating thermal stability. The test is performed by reaching temperatures above the calcination temperature.

2.2- DILATOMETRY

Dilatometry (ASTM- E228 DIN 51045- 1/ 5) allows for the registration of changes in the length of a specimen as a function of temperature. Considering that any reaction involving a phase change or appearance of liquid causes volumetric changes in the samples, this technique enables dynamic monitoring of the reaction and sintering processes that occur during the thermal cycle of the parts. In sintered ceramics, this measurement is useful for evaluating thermal stability. The test is performed by reaching temperatures above the calcination temperature.

2.3- THERMAL SHOCK RESISTANCE

This test consists of measuring the loss of microstructural integrity (micro-cracking) after cycles of abrupt temperature changes, depending on the intensity of the gradient or depending on the cold-hot cycle. Microstructural integrity is evaluated through a property (compression, modulus of rupture, and/or modulus of elasticity). The test is conducted under guidelines from standards IRAM 12616 and ASTM 1171.

3. TEXTURAL ANALYSIS

DENSITY AND POROSITY

The density and porosity of ceramics are measured by the Archimedes method (ASTM C373-88- 2006). Both measurements are correlated. This is a test on the fired material to determine the % of empty volume in a given body (porosity) and the amount of mass in a certain volume of substance (density). This property is conditioned by the degree of vitrification of the paste or gresification, which, in turn, will determine other properties of the material such as mechanical resistance to stress (compression, bending, traction), wear resistance, chemical attack resistance, hardness, impermeability, etc.

The percentage open porosity (P) is the ratio between the volume of open pores and the volume of the material expressed as a percentage.

Bulk density is the ratio between the weight of the dry sample and its apparent volume (which includes the pores).

4. MICROSTRUCTURAL ANALYSIS

SCANNING ELECTRON MICROSCOPY

Scanning Electron Microscopy (SEM Scanning Electron Microscopy) is a useful tool for performing microanalysis of ceramics. It has a magnification capacity of up to 20,000 times. Its main applications include: microstructural characterization, identification of crystalline phases and phase transitions, surface composition, surface topography, and grain size determination, among others.

5. MINERALOGICAL ANALYSIS

X-RAY DIFFRACTION

X-ray diffraction allows for the identification and/or quantification (Rietveld Method) of crystalline phases present in ceramics.

The application of this technique can have many purposes that allow establishing criteria on certain behaviors of ceramics (hardness, resistance, etc.).

6. MECHANICAL BEHAVIOR

❖ MODULUS OF RUPTURE

The modulus of rupture, often abbreviated as MOR, (sometimes called flexural strength), is a parameter of great utility for characterizing the mechanical strength of ceramic materials before their rupture. The guidelines of ASTM C1161-02 are followed for this purpose.