The characterization of Fe-rich phases in a high-pressure die cast hypoeutectic aluminum-silicon alloy. (15th August 2020)

• Record Type: Journal Article
• Authors: Jiao, X.Y.; Liu, C.F.; Guo, Z.P.; Tong, G.D.; Ma, S.L.; Bi, Y.; Zhang, Y.F.; Xiong, S.M.
• Is Part Of: Journal of materials science & technology. Volume 51(2020)
• Page Start: 54
• Page End: 62
• Publication Date: 2020-08-15
• Subjects: Hypoeutectic Al-10Si -- Fe-rich phases -- Fracture morphology -- High pressure die casting; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2020.02.040
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: Both microstructural characteristics and fracture behavior of Fe-rich phases in a high-pressure die-cast hypoeutectic Al-Si alloy were investigated. Attention was focused on the morphology and formation mechanism of Fe-rich phases, together with their influence on fracture. Results show that primary Fe-rich phases exhibited in blocky shape precipitated from liquid while secondary Fe-rich phase in a large net shape was distributed along eutectic boundary participating in a ternary eutectic reaction. Through synchrotron X-ray tomography characterization, three Fe-rich phases with different morphologies, i.e., polyhedral shape, fine compact shape and Chinese script-type shape were extracted along the radial direction. Lower slow-shot speed promoted the polyhedral Fe-rich phase to precipitate in slow-shot sleeve while decreased the formation of fine compact and Chinese script-type Fe-rich phases in die cavity. Because of a worse deformation compatibility, polyhedral Fe-rich phases fractured and became stress concentration sources before the failure of the casting.