logo Page 2

Research Papers Copyright MeltLab Systems

 
 
 
Our research papers are attempts to take a comprehensive look at an aspect of thermal analysis. Some have been published and are only available though AFS. We reference those here. Others are presented here free of charge. Shorter papers are generally presented in our Hot Topics sections and have fewer references. Please check there as well.
 
  • Improving the accuracy of TA Thermal analysis is a fast and inexpensive way to see if a furnace of metal meets the basic criteria for pouring. Often melting is the bottleneck of a foundry and having a furnace of iron or aluminum or copper alloy on hold for the laboratory results can be costly. Some foundries have great success with thermal analysis results while others have problems with inaccuracy. This paper tries to cover all the sources of inconsistency and how to correct them so that foundries can get the most good out of these instruments.

  • Ductile Nodularity by Thermal Analysis Abstract: This initial paper shows how MeltLab measures the smoothness of the curve to determine the degree of nodularity of a final ductile iron sample. Taking the casual observance of Dr. Lampic, we have turned up a surprisingly reliable way to measure the growth shape of graphite by bursts of energy produced by the growth of vermicular graphite. This method is ideally suited to MeltLab's strong points of precision, noise suppression, and derivative calculation.

  • Ductile Microstructure by Thermal Analysis Abstract: A thought paper showing how different aspects of the thermal analysis curve indicate different aspects of microstructure including pearlite, hypereutectic(solid riser prone), hypoeutectic (more shrinkage prone), and eutectic (ideal). Shrink and carbides can be seen. The potential is there to give a very quick micro analysis from molten iron in just 3 to 4 minutes.

  • Offsetting Ductile shrinkage The natural shrinkage that occurs during the solidification of Ductile Iron can be offset by the expansion caused by the formation of graphite. Though this has been known for some time, thermal analysis has some interesting contributions to understanding exactly what is going on, and offers some opportunities for better control of late graphite expansion in moderate section sizes. Different modes of solidification are examined and measured, and the early and late graphite content are calculated using thermal analysis. Carbon flotation is seen as a fourth form of solidification that is both hypereutectic and hypoeutectic. Shrinkage is seen as a lack of late graphite growth needed to offset the natural contraction of the Ferrite. Grain boundary shrinkage can be seen as an escape mechanism for minor unfulfilled contraction. Stress relief heat treat increases the graphite volume thereby collapsing any remaining of the grain boundary shrinkage and improving fatigue life and other physical properties.



Reducing noise in Thermal Analysis Filtering Signal vs noise


Nodularity signal from 4th derivative Nodularity signal


Ferrite and Pearlite curves Ferrite and Pearlite curves


Shrinkage example Shrinkage example