Thermal Brazing Expansion Coefficient
The thermal expansion coefficient for brazing indicates how the length of a material changes with temperature. Large differences between base metal and filler metal lead to high residual stresses in the joint.
Physicochemical mechanism of action
The thermal expansion coefficient of a material describes how its length changes when temperature changes. This coefficient varies by material and is especially important for joints of dissimilar metals.
Metallurgical relevance & welding risks
When the thermal expansion coefficients of base material and filler metal differ, high residual stresses build up in the joint. These can lead to cracking, fracture, or reduced mechanical properties. This is especially critical at high temperatures and during long heat treatments.
Workshop practice & action instructions
To minimize risks, take the following measures:
• Use filler metals with a thermal expansion coefficient similar to that of the base material.
• Keep heat treatment short and precise.
• Regularly check the mechanical properties of the welded joints.