Encyclopedie de la recherche sur l'aluminium au Quebec - Edition 2014 | 页面 68

66 Spark plasma sintering of an Al-based powder blend for automotive applications FRITTAGE À CHAUD AVEC CHAMP ÉLECTRIQUE PULSÉ D'UN MÉLANGE TRANSFORMATION ET APPLICATIONS // TRANSFORMATION AND APPLICATIONS DE POUDRE À BASE D'Al POUR DES Frittage à chaud avec champ APPLICATIONS AUTOMOBILES électrique pulsé d’un mélange de poudre à base d’Al SPARK PLASMA SINTERING OF AN Al-BASED pour des applications automobiles POWDER BLEND S. Rudinsky1, J. Aguirre1, G. Sweet2, J. Milligan1, D.P. Bishop2 et M. Brochu1 1 Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, QC, Canada, H3A 0C5 2 Department of Process Engineering and Applied Science, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada, B3J 1Z1 INTRODUCTION ¥  Increasing air pollution and cost of energy consumption have directed research into fuel efficiency in automobiles. ¥  Using aluminum parts reduces overall weight of vehicles compared to steel parts. Al-Si alloys are of interest in the automotive industry due to their high strength, high wear resistance, low coefficient of thermal expansion, and low density1. ¥  Powder metallurgy (PM) reduces production time and cost through consolidation of metal powders instead of machining bulk material. ¥  Spark plasma sintering is an advance in PM that further reduces cost and time, while creating a superior part. The assembly is placed inside a vacuum chamber through which the current passes. Spark plasma sintering (SPS) is a sintering technique that applies both a uniaxial pressure and a pulsed D.C. to induce joule heating. A powder specimen is placed inside a conductive die between two punches. Current passes through the particles which creates resistance (joule) heating at the contact points generating high heating rates at these contacts and causing rapid consolidation. OBJECTIVES ¥  Typically, pre-alloyed powders are sintered using SPS. We i