Date of Award
Doctor of Philosophy
Industrial and Manufacturing Engineering
Dr. Sam Ramrattan
Dr. Steven Butt
Dr. Leonard Lamberson
Dr. Tarun Gupta
Aeration sand filling is a new molding technique in foundry. Using this technique, sand with smooth flow can be filled in any orientation and shape using low-pressure air. This is not possible by conventional gravity and high-pressure blow filling techniques. Aeration was introduced as an energy-efficient and environmentally- friendly sand molding technique. In addition, aeration has its niche on quality of molds it could produce. Friability, one of the crucial green properties for the quality mold was significantly low in aeration in comparison to the gravity and high-pressure blow filling. The fluidization action in aeration acted upon the sand clay interfaces and created the interactions with them, and induced better surface abrasive property. In other words, aeration lowered the friability in the green sand allowing a lower compactibility levels in green sand molding, which was not possible with the conventional molding techniques. The range of 30-35% was suggested as the optimal working range of compactibility for aeration molding technique for selected sand and clay composition.
Advance cone jolt and thermal erosion tester were developed and used to examine the green sand properties of the foundry sand. Advance cone jolt was sensitive to the clay composition and contamination in green sand, whereas thermal erosion tester demonstrated its relevance in evaluating mold surface behavior at an elevated temperature. Thermal erosion test displayed less sand erosion in the molds built in the aeration.
Green sand in aeration was benefited by the favorable clay orientation. Homogeneous and isotropic distribution of clay platelets occurred during fluidization, which produced a better clay coating on the sand grains and increased the grain to grain bonding. Scanning electron microscope displayed a uniform clay coating and universal micro-tribometer showed greater bonding strength in the surface of the molds produced in aeration. Casting trial along with the relevant standard AFS tests for green sand properties were carried out, and analyzed using design of experiments and statistical tools.
Paudel, Ananda Mani, "Optimizing Green Sand Properties of Fluidized Sand from Aeration and Developing New Green Sand Testing Technique" (2010). Dissertations. 618.