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The Future of Metalcasting Through New Ideas and Innovation


A sampling of presentations from the AFS Metalcasting Congress in Milwaukee focuses on ways to move the industry forward into a new period of prosperity. A MODERN CASTING STAFF REPORT


sampling of completed research proj- ects. Tey are shared and discussed and hopefully help metalcasters across North America improve their operations, better service customers, and stay ahead of the game in a very competitive market. Tree of the presentations are


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summarized below. Tese papers from some of the leading minds in the industry represent studies and ideas that could have wide-ranging positive impacts on the future of metalcasting.


PRESENTATION Process Simulation and Experimental


Validation of Resin-Bonded Silica Sand Mold Casting


AUTHORS Yan Lu, Hulmin Wang and Alan


Luo, Ohio State University (Columbus, Ohio); Keith Ripplinger, Honda Engi- neering North America (Anna, Ohio).


BACKGROUND Sand casting is the most commonly


used casting process. Components with intricate cavities can be cast by inserting cores made of foundry sand. Of all the aggregates used to produce sand molds and cores, silica sand is the most popular in producing highly di- mensionally accurate castings at a cost more favorable than other materials


48 | MODERN CASTING May 2017


ne of the biggest draws of the annual AFS Met- alcasting Congress is the


such as zircon, chromite, and mullite ceramic. In molding operations, resin binders and hardeners are generally added into silica sand. Sand with these mixtures is called resin-bonded sand, and it typically consists of 93-99% silica and 1-3% binders. Simulation technology has made


remarkable progress in casting design and process optimization prior to actual manufacturing, which reduces the time and cost of conventional trial-and-error methods. Although many experiments have been done to study sand molds and cores, simulation techniques for predicting and controlling them are still underdeveloped due to the com- plex mechanical behavior and failure mechanisms of sand materials. Tus, it is necessary to develop reliable and ro- bust process simulation models of sand


molds/cores for more efficient manufac- turing. In the present study, mechanical tests of resin-bonded silica sand with 98.7% silica and 1.3% phenolic resin binder were performed. Experimental data from mechanical tests, together with some key data from literature, were used to build a material model for sand molds/cores for casting process simula- tion. Ten, casting simulation for three different geometries of sand cups was performed, and corresponding experi- mental validation was carried out.


CONCLUSION


1.3% phenolic resin binder was studied to develop a material model for casting process simulation. Tirty-six three- point bending tests were completed with an average fracture stress of 3.233 MPa and a standard deviation of 0.585. Inelastic behavior of this sand was found and elastic modulus was mea- sured as 2,300 MPa from the three- point bending tests. Density was also obtained from three-point bending samples as 1,628 kg/m3


A commercial resin-bonded silica sand mixture with 98.7% SiO2


and . Seven uniaxial


This is a uniaxial tensile test for a dog-bone sample on a standard MTS testing system.


tensile tests were performed with an average UTS of 1.450 MPa and a stan- dard deviation of 0.258. Te data from mechanical tests are used to establish a material model for sand molds/cores in casting process simulation. Tree types of sand cup molds were made and poured with A356. Stress was


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