A significant number of inserts were designed and fabricated over the span of the project, primarily for squeeze casting different configurations of test bars and plates. Subsequently, a Sterling oil die heater and a Visi-Track shot monitoring system were added. The challenge of installation and operation of such industrial-size equipment in an academic environment was met successfully. A Lindberg 75k W electrical melting furnace was installed alongside. This study was initiated with the installation of a new production size UBE 350 Ton VSC Squeeze Casting system in the Metal Casting Laboratory at Case Western University. Unalloyed steel did not have the required strength or mechanical properties to increase the properties of the casting. Rather than a sudden failure occurring, the reinforcement of the stainless steel wire or the punched hard stainless steel sheet held the material together and prevented any loss of the fractured casting to the surroundings. Higher loads to failure were obtained because of the reinforcement of the stainless steel wire and punched sheet. However, when the ability of the casting was tested under the compressive force of a plunger, the strengthening effect of wire mesh or sheet was evident. Only a slight improvement in strength could be determined because of water leaks at the seal between hemispherical dome and its flat supporting side. This dome shape casting has been produced both with and without reinforcement and tested to determine its pressure resistance under internal pressure of water. The use of higher pressure to produce the squeeze casting has been shown to increase the strength of a hemispherical dome casting. Good strength can be obtained with a sound die casting without any defects produced by squeeze casting. The lowest results were obtained with unreinforced 356 aluminum casting. When the annealed 1020 steel wire mesh was used, the results were only slightly improved because of the lower mechanical properties of this unalloyed steel. Somewhat lower results were obtained with the annealed punched stainless steel sheet.
The best strengthening was obtained with austenitic stainless steel wire and with a punched stainless steel sheet without annealing this material. The use of reinforcements made of austenitic stainless steel wire mesh or punched austenitic stainless steel sheet provided marked improvement in reducing the fragmentation of the casting. The tendency of aluminum cast enclosures to fracture could be significantly reduced by installing a wire mesh of austenitic stainless steel or a punched austenitic stainless steel sheet within the casting. A deep drawing die was used to fabricate the reinforcing performs. A hemispherical, dome shaped casting was selected in this investigation. Such performs can be fabricated from steel wire mesh or perforated metal sheet by stamping or deep drawing.
A practical approach to reinforcement of die cast aluminum components is to use a reinforcing steel preform. Also toughening of A354 aluminum cast alloy by steel and stainless steel wire mesh with various conditions was analyzed. Bonding of Aluminum bronze, Cast iron, and Ni-resist inserts with various electroplated coatings and surface treatments were more » analyzed. The initial work was conducted in sand molds to create experimental conditions that promote prolonged contact of the reinforcing material with molten aluminum.
A number of potential reinforcement materials were investigated. In case of a failure, unless adequately contained, fractured parts could injure people operating the equipment. A typical example would be a supercharger. The utilization of aluminum die casting as enclosures where internal equipment is rotating inside of the casting and could fracture requires a strong housing to restrain the fractured parts. This increase in tolerance to Fe impurities can lead to a substantial reduction in manufacturing costs due to (1) reduced raw-material costs, (2) reduced die sticking, and (3) improved die life. fatigue strength (r = 0.5 pct for the gravity die cast LM25 + Fe alloy in the T6 heat-treated condition. Compared to A 356 T6 values in brackets, the new alloy has yield strength > 21 ksi (> 32 ksi) tensile strengths > 42 ksi (43 ksi) and elongation > 15% (10%) in temper F. For this reason, the authors were challenged to develop an alloy that provides sophisticated mechanical properties without any heat treatment. That means solution heat treatment and quenching and artificially aging. To get high mechanical properties using standard squeeze casting alloys (for example A356) it is indispensable to make a heat treatment.
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