Inverse Gravity Segregation
Inverse gravity segregation is an anomalous distribution of alloying components contrary to the direction of gravity during solidification, caused by volume contraction and flow effects in the residual melt. This leads to uneven stresses and can cause cracking or deformation.
Physikalisch-chemischer Wirkmechanismus
Inverse gravity segregation occurs when the alloy components are not evenly distributed during solidification. This often happens due to volume contraction and flows in the remaining molten metal. The components accumulate at certain spots, leading to uneven stresses.
Metallurgical Relevance & Welding Risks
Inverse gravity segregation can lead to cracks and distortion in the weld metal. These can occur especially when the melt time is too short or the temperature is not optimally set. The stresses can also affect the microstructure and reduce strength.
Werkstattpraxis & Handlungsanweisungen
To avoid inverse gravity segregation, the melt time should be long enough to ensure an even distribution of the alloy components. The temperature should be set so that no uneven stresses occur. For heavy materials or under high restraint, it is especially important to precisely control melt time and temperatures.