Simple Solutions That Work! Issue 14

FRANÇOIS AUDET Solutions Fonderie ARTICLE TAKEAWAYS: • Could you shorten the melt treatment and increase the number of molds poured? • How do the solidification properties of your melt vary during production? • What is the cooling curve in your simulation software versus your shop floor? • Advanced thermal analysis data are simple to collect and profitable for the foundry I ron foundries make their metallurgy from raw materials Aluminum foundries buy their metallurgy from ingot manufacturers. While this article focuses on thermal analysis of liquid aluminum-silicon alloys, the general principle applies to any melt: you can have the same target chemistry and apply the same cooling rate and still measure a different solidification behavior from pour to pour if you don’t fully control the molten metallurgy. Let’s look at this 8 minute shop-floor test to advance your castings. THERMAL ANALYSIS MADE SIMPLE Thermal analysis systems for aluminum-silicon alloys are used by both researchers and shop floor operators. While more European foundries benefit from it than Americans, one of the drawbacks has been ease-of-use and interpretation right on the shop-floor. What the operator really needs is to know if his melt is within specs or if he should call the supervisor about it (figure 1). Only then, the metallurgist can work with numbers instead of feelings to publish great work instructions for the operators based on live melt solidification properties, and fading of those over time. How do you decide when to add flux, titanium, strontium and magnesium? How much? How should we adapt melt practices based on casting quality requirement? The spectrometer chemistry is not enough. It’s revealing to see the wide distribution of melt treatment work instructions according to the November 2016 survey in Modern Casting (figure 2). COOLING CURVE GO-NO-GO ANALYSIS FOR THE FURNACE OPERATOR ADVANCED MANUFACTURING SOLUTIONS Continued on next page 13 Figure 1. Thermal analysis interface for the furnace operator