Search Results for hypoeutectic alloys

The 443 series of aluminum casting alloys have nominal silicon content of 5 wt% with various limits on iron, copper, manganese and magnesium. They are hypoeutectic AI-Si binary alloys with high ductility, very good corrosion resistance, good machinability, but only fair castability, and low strength. The alloys are used in castings where above average ductility coupled with excellent corrosion resistance is needed. This datasheet provides information on key alloy metallurgy, fabrication characteristics, processing effects on physical and mechanical properties, and application characteristics of these alloys.

This article focuses on aspects that are important for the commercial production of castings. It discusses the modification process in hypoeutectic and eutectic alloys that differ only in the relative volume fraction of primary aluminum and aluminum-silicon eutectic. The article explains how modification changes porosity formation in a casting. It describes the mechanisms responsible for silicon modification, as well as the modifications and changes in eutectic nucleation and the eutectic grain structure. The article reviews the usage of strontium in foundry practices. The growth of silicon eutectic is described to explain effects ancillary to silicon modification. The article also examines the effects of elements, such as phosphorus, antimony, bismuth, magnesium, boron, and calcium, on the silicon structure.

This article illustrates the equilibrium phase diagram for an aluminum-silicon system, showing the metastable extensions of liquidus and solidus lines. It describes the classification and microstructure of the aluminum-silicon eutectic. The article presents the theories of solidification and chemical modification of the aluminum-silicon eutectic.

This article describes different methods by which the composition of cast iron can be analyzed. It provides particular emphasis on the methods for evaluating the graphitization potential of a melt with prescribed limits on carbon, silicon, and alloying elements. The article discusses the effect of cooling rate on the graphitization of a given composition by chill and wedge tests. Thermal analysis of cooling curves gives excellent information about the solidification and subsequent cooling of cast iron alloys. The article presents some applications of the cooling curve analysis and explains the evaluation of carbon-silicon contents, graphite shape, graphite nucleation, and contraction-expansion balance. It illustrates the use of an immersion steel sampling device for compacted graphite iron production and provides information on the ferrite-pearlite ratio in ductile iron.

This article focuses on the tribological behavior of group 1, 2, and 3 cobalt-base alloys, namely, carbide-type wear-resistant alloys and laves-type wear-resistant alloys. The behavior includes hardness, yield strength and ductility, and fracture toughness. The article contains a table that lists the nominal compositions and typical applications of cobalt-base alloys. It discusses the properties and relative performance of specific alloys when subjected to the more common types of wear. These include abrasive wear, high-temperature sliding wear, rolling-contact fatigue wear, and erosive wear.