Argen Testing

THERMAL PROPERTIES

Thermal Expansion Coefficient

This number represents the percentage of dimensional change one can expect per unit increase in temperature. The coefficient is measured with a dilatometer which records the change in a sample length over a range of temperature. Thermal expansion is a very important parameter for dental alloys used for porcelain application.

Melting Range

The melting range of an alloy is the range from the temperature at which the liquid metal begins to solidify (liquidus) to the temperature at which solidification is complete (solidus). The melting range is determined using a Perkin-Elmer Model DTA 1700 Differential Thermal Analyzer. Most dental alloys are solid solutions in which the difference between the solidus and the liquidus can vary form approximately 10°C to 159°C. Pure metals solidify at a single defined temperature.

Heating Treating Parameters

The mechanical properties of an as-cast dental alloy can be modified by heat treatment or annealing processes. This also applies to cold worked materials which must be softened in order to achieve the dimensions required by additional mechanical force. The most important parameters influenced by subjecting the alloy to specified temperatures for specific times followed by either quenching or air cooling are hardness, strength and elongation. The heat treating parameters are usually expressed in terms of annealing temperature and the amount of time that the metal must be held at that temperature.

Thermal Stability (sag resistance)

The property is important for alloys which will be coated with porcelain. The test consists of measuring the deformation of a 10 mm x 1 mm x 50 mm strip of alloy under its own weight at 980°C.

BIOCOMPATIBILITY

CORROSION RESISTANCE

TARNISH TEST

PHYSICAL/MECHANICAL PROPERTY TESTS

THERMAL PROPERTIES

PRACTICAL APPLICATION TESTS

QUALITY ANALYSIS TESTING