Abstract
In the present paper, Natural Metal-Matrix Composites (NMMC) based on multicomponent hypereutectic Al-Ca-(Mn)-(Ni) alloys were studied in as-cast, annealed and rolled conditions. Thermo-Calc software and microstructural observations were utilised for analysing the equilibrium and actual phase composition of the alloys including correction of the Al-Ca-Mn system liquidus projection and the solid phase distribution in the Al-Ca-Mn-Ni system. A previously unknown Al10CaMn2 was discovered by both electron microprobe analysis and X-ray studies. The Al-6Ca-3Mn, Al-8Ca-2Mn, Al-8Ca-2Mn-1Ni alloys with representative NMMC structure included ultrafine Ca-rich eutectic and various small-sized primary crystals were found to have excellent feasibility of rolling as compared to its hypereutectic Al-Si counterpart. What is more, Al-Ca alloys showed comparable Coefficient of Thermal Expansion values due to enormous volume fraction of Al-based eutectic and primary intermetallics. Analysis of tensile samples’ fracture surfaces revealed that primary intermetallics may act either as stress raisers or malleable particles depending on their stiffness under deformation. It is shown that a compact morphology can be achieved by conventional casting without using any refining agents. Novel hypereutectic Al-Ca NMMC materials solidifying with the formation of Al10Mn2Ca primary compound have the best ductility and strength. We reasonably propose these materials for high-load pistons.
Highlights
Light materials with a given set of mechanical and physical properties are extremely in demand for manufacturing engineering parts [1,2,3]
Experimental investigations investigations were conducted for revision revision of of the the isothermal isothermal fields
Ca primary primary crystals crystals were reported with coarse platelet shape [7], most ofofthe theselected selected compositions encountering crystallisation the primary
Summary
Light materials with a given set of mechanical and physical properties are extremely in demand for manufacturing engineering parts [1,2,3]. Hypereutectic Al-Si alloys (e.g., A390.0 and FM180 alloys), have been established due to acceptable performance in the aforementioned properties [1,4,5] In reality, they are natural metal matrix composites (NMMC) consisting of hard (Si) crystals distributed throughout a eutectic matrix. When considering hypoeutectic Al-Ca alloys, they have low density, an appropriate combination of mechanical properties and corrosion resistance [6,8]. The reported Al-Ca-Mn-Fe alloys with a set of superfine multiphase eutectics (ternary and work [13] reported Al-Ca-Mn-Fe alloys with a set of superfine multiphase eutectics (ternary quaternary) that provides a high-tech performance in casting and metal forming.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
