JBS Technologies (United States)

Abstract This article reviews the basic types of mold aggregates and bonding methods for expendable molds and coremaking. It provides an overview of mold media and the basic types of sands and their properties. The most significant clays used in green sand operations, such as bentonites, are discussed. The article describes the methods of sand bonding with inorganic compounds. It provides a description of resin-bonded sand systems, namely, no-bake binder systems, heat-cured binder systems, and cold box binder systems. The article concludes with a discussion on the media used for expendable molds, namely, ceramic shells and rammed graphite, for casting reactive metals such as titanium or zirconium.

Abstract Primary silicon in hypereutectic aluminum-silicon alloys is very hard, not only imparting improved wear resistance but also decreasing tool life during machining. This article discusses the importance of primary silicon refinement and the process of accomplishing primary silicon refinement.

not Available.

We report for the first time results on infusion doping of boron for ultra shallow junctions (USJ). Using B/sub 2/H/sub 6/ or BF/sub 3/ source gas, the resulting USJ boron dopant profile measured by SIMS shows no evidence of channeling with extreme abruptness of <2.5nm/decade for a 12 nm shallow junction. Infusion doping shows a power log to the 1/3 relationship between energy to junction depth in contrast to the traditional linear fit observed with ion implantation due to nuclear stopping power effects. Boron surface doping levels of 1-2E22/cm/sup 3/ for 2E16/cm/sup 2/ doses were achieved. Dopant activation using low temperature furnace annealing from 450/spl deg/C to 950/spl deg/C were compared using standard 4PP and non-penetrating elastic material 4PP for sheet resistance measurements,on these USJ structures. Also, electrically active dopant profiling was conducted using spreading resistance profile (SRP) for USJ junction depth (Xj) comparison to SIMS. Use of amorphizing implantation resulted in lower Rs values after low temperature SPE annealing.