Effects of silicon on the metallurgy and sintering response of Al–Ni–Mg PM Alloys

✍ Scribed by I.A. MacAskill; D.W. Heard; D.P. Bishop

• Book ID: 104063245
• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 864 KB
• Volume: 452-453
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2006.11.038

✦ Synopsis

In this investigation the effects of minor amounts of silicon on the sintering response, microstructure, and mechanical properties of experimental Al-Ni-Mg PM alloys were assessed. Associated experimental techniques included thermal dilatometry, pilot-level sintering trials, EPMA, XRD, apparent hardness measurements, and tensile testing. A sequential approach of study advancing through binary (Al-Mg), ternary (Al-Mg-Si and Al-Ni-Mg) and quaternary (Al-Ni-Mg-Si) systems was adopted. It was found that silicon additions promoted the formation of a persistent liquid phase and ultimately diffused into the ␣-aluminum grains. Only trace levels were detected in the Al 3 Ni intermetallic. Despite this limited chemical interaction, silicon significantly altered the morphology of Al 3 Ni in alloys of low nickel content. Silicon also imparted a natural age hardening effect in several alloys and positive gains in yield strength and UTS for all.