What is Thermal Analysis? 2014 A Thermal Analysis approach by MeltLab Systems 844-MeltLab Fast  Accurate  Comprehensive

What is Thermal Analysis? In general, thermal analysis looks at the thermal events in the liquid-solid phase transformation to spot changes in the way atoms arrange themselves in different crystal structures. Specifically in Foundry TA, we take a sample of molten metal and see what happens as the metal cools. This can tell us about fluidity, chemistry, microstructure, inoculation, gases and shrinkage.

History – Scientific In the early 1900’s scientists started investigating pauses in the solidification of metals known as arrests. Here is some early work on iron arrests. Today, we have better data.

Scientific tools: DTA Differential Thermal Analysis is a term for an instrument that can raise or lower the temperature of a sample and measure these temperature arrests. The instruments are complicated and expensive, and generally work on solid materials, not liquid. lysis They require highly trained technicians and can cost up to $150,000 – not exactly filling the needs of foundries.

Foundry Tools - History The first temperature analysis was done to just find the C.E. arrest and helped determine the fluidity of iron. Then in the 1960s a foundry educational group known as the Gray Iron Research Institute (GCRI) developed a system with a hand held calculator to measure the liquid and solid arrest in white iron and calculate C.E. and carbon based on the ITPS 1947 standard. From those two temperatures they were able to estimate silicon (source Bill Shaw). The British Cast Iron Research Institute confirmed the research though they used a different equation for silicon and worked off of the more recent ITPS 1960 standard.

Foundry Tools – History Cont. GIRI changed into the present day ICRI or Iron Casting Research Institute, and Bill Shaw rose to become Chairman, and finally to retire. The technology they developed was turned over to Leeds and Northrup to manufacture. ElectroNite then entered the market, was swallowed up by Heraeus, and then bought out the metallurgical division of L&N. Today ElectroNite dominates the TA consumable industry in North America.

What is an arrest? An arrest is a pause in the cooling rate because crystals of one kind or another are forming. This graph shows a liquidus arrest with some undercooling. One major competitor mistakenly takes the undercooling temperature as the liquidus, however, the peak of liquidus, called the growth temperature by Dr. Bäckerud, is the correct point.

What are derivatives? Derivatives are the rate of change of the primary temperature curve. They are far more sensitive and useful in finding small arrests and in finding the start and stop of an arrest if you want to measure the total energy of an arrest. In this case the cooling rate is about 100x more sensitive than the temperature curve, and the 2 nd derivative is about 1,000x more sensitive.

Thermal Analysis Instruments MeltLab® came along in late 1990 as the first computerized foundry TA unit and quickly gained a large share of the market. It was sold first through L&N, then MINCO, and finally marketed directly by MeltLab Systems. There are many differences between MeltLab and the other offerings on the market that will be covered in later presentations, but here are the three main ones, and one bonus:

Fast  Accurate  Comprehensive Speed of analysis: While all systems need to wait on the temperature to drop to the arrest temperature, our system instantly calculates charge correction, flags out-of-range, and shares the data over the network. If you are using our ProcessWindows© application, the results of your thermal analysis can instantly appear on any computer on your network.

Fast  Accurate  Comprehensive Accuracy: all of our competitors have issues with accuracy because they struggle with the mathematics of derivatives and smoothing. We have struggled as well, but over the years have continued to improve our smoothing and detection routines (while our competitors play catch-up and are years behind).

Fast  Accurate  Comprehensive Comprehensive: Our competitors can’t do what we do, so they refer to the extras as “bells and whistles”. We call it being comprehensive. We were the first to add the solidus arrest, oxide arrests, shrinkage arrests, and the furnace correction additions of carbon and silicon. We pioneered long term archiving of curves, and to add daily result spreadsheets on the network. We continue the practice of continued process improvements of our software with new releases several times a year. Do any of our competitors do this?

Extra bonus: MeltLab is Long Lasting Long Lasting: MeltLab hardware has a 5 year warranty on our electronic parts, however we are extending it to 10 years as of January Why? Because we noticed that the MeltLab hardware box and its electronic components are lasting up to 20 years! Would you buy a competitor's system with just a one- year warranty? The length of their warranty indicates how reliable their system is—and so does ours!

MeltLab Systems® Fast  Accurate  Comprehensive Subscribe to our s Phone 844-Meltlab