Qualification of Chemically Bonded Sand Systems Using a Casting Trial for Quantifying Interfacial Defects

Ramrattan, Sam; Wells, Lee J.; Patel, Pinakin; Shoemaker, Jay

doi:10.1007/s40962-017-0166-3

Cited by 8 publications

(2 citation statements)

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“…The highest value of dilatation is found in monofraction sand with rounded grains. In [ 18 ], the most effective approach to prevent stress defects is to replace the sand with another sand with lower thermal expansion (deformation) values, without phase transformations [ 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Effect of the Composition of Hybrid Sands on the Change in Thermal Expansion

et al. 2022

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In the foundry industry, silica sands are the most commonly used type of sands for the production of sand foundry moulds using various types of binders. Their greatest disadvantage is their significant volume changes at elevated temperatures, which are associated with the formation of many foundry defects from stress, such as veining, and thus have a direct influence on the final quality of the casting. In the case of non-silica sands and synthetic sands, the volume stability is more pronounced, but this is accompanied by a higher purchase price. Therefore, a combination of silica sand and synthetic sand CERABEADS is considered in order to influence and reduce the thermal expansion. The hybrid mixtures of sands, and their most suitable ratios, were evaluated in detail using sieve analysis, log W and cumulative curve of granularity. It was found that the addition of 50% CERABEADS achieves a 32.2% reduction in dilatation but may increase the risk of higher stresses. The measurements showed a significant effect of the granulometric composition of the sand on the resulting thermal expansion, where the choice of grain size and sorting can achieve a significant reduction in dilatation with a small addition of CERABEADS.

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Section: Introductionmentioning

confidence: 99%

Effect of the Composition of Hybrid Sands on the Change in Thermal Expansion

et al. 2022

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“…26 Instruments were developed for measuring the hot-distortion parameters such as the Hot-Distortion Tester, 26 DMA apparatus, 27 and its modified instruments 28 or the Thermal Distortion Tester. 29 Several high-temperature deformation-related experiments [30][31][32][33][34][35][36][37][38][39][40][41][42][43] were conducted on different organic and inorganic bonded sand cores. Dobosz et al 17 investigated the hot-distortion properties of no-bake sands.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Acid Hardener on the Strength and Hot-Distortion Properties of No-Bake Sand Cores

2021

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In this research work, the effects of different amounts of acid hardener (30%, 40%, 60%, 80% weighted to the resin) on the hardening characteristics and hot-distortion properties of no-bake furan and no-bake phenolic bonded sand cores were studied. Bending tests were conducted on test bars with storage times of 1, 2, 3, 5, 7, 24h. Hot-distortion tests were carried out on specimens with storage times of 4h and 24h. The bending tests revealed that in the case of the furan binder system, the acid hardener is best utilized in terms of higher bending strength, in an amount of 40–60%, while in the case of the phenolic binder system, the amount of 60–80% acid hardener resulted in higher bending strength of the sand specimens. Too low (30%) acid hardener (catalyst) level produced low bending strength. Too high (80%) amount of acid hardener decreased the strength of the no-bake furan sand samples, and as can be seen from the SEM analysis, it damaged the binder bridges between the sand grains. The hot-distortion tests showed that there is a correlation between the catalyst content and the max. Deformation of the samples both in the furan and in the phenolic no-bake sand cores, which can be described with a maximum curve. Increasing the acid hardener changes the thermoplastic behavior of the phenolic resin, thus the binder bridges become more rigid and brittle. The acid hardener above 40% decreased the thermal stability of the furan and phenolic bonded test pieces. The research work also revealed significant differences between the specimens made with furan and phenolic binder and the effect of the storage time in terms of the bending strength and hot-distortion properties.

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