Fabrication and Characterization of High-strength Water-soluble Composite Salt Cores via Layered Extrusion Forming

International Journal of Metalcasting (2022)Cite this article

Abstract

This paper presents a novel process for preparing high-strength water-soluble salt cores with complex structure via layered extrusion forming using K2SO4 and KCl as the base salt materials, which is suitable for manufacturing hollow complex-shaped castings. The effects of fortifiers including alumina powder, sericite powder and silica powder on properties and microstructures of K2SO4–KCl composite salt cores were systematically investigated, and the strengthening mechanisms of the composite salt cores are discussed. The results indicate that the effect of alumina powder on the bending strength of K2SO4–KCl composite salt cores is significantly better than that of sericite powder and silica powder. When the content of alumina powder is 20 wt.%, the composite salt cores possess excellent comprehensive properties, and their bending strength, linear shrinkage, water-solubility rate, and moisture rate are 23.34 MPa, 13.86%, 76.73 g/(min·m2), and 0.11%, respectively. The proper content of alumina powder can refine the size of KCl grain and obtain a denser microstructure. Finally, the composite salt core components with high strength and complex structure were fabricated by using the optimized process parameters.

Korea Abstract

본 논문은 중공 복합형 주물 제조에 적합한 K2SO4와 KCl을 기본염 재료로 사용하여 층상 압출 성형을 통해 복합 구조의 고강도 수용성 염심을 제조하는 새로운 공정을 제시한다. 알루미나 분말, 견운모 분말 및 실리카 분말을 포함한 강화제가 K2SO4-KCl 복합염 코어의 특성 및 미세 구조에 미치는 영향을 체계적으로 조사하고 복합 염 코어의 강화 메커니즘을 논의하였다. 결과는 K2SO4-KCl 복합염 코어의 굽힘 강도에 대한 알루미나 분말의 효과가 견운모 분말 및 실리카 분말보다 훨씬 우수함을 나타냅니다. 알루미나 분말의 함량이 20wt.%일 때 복합염심은 우수한 종합특성을 가지며 굽힘강도, 선수축율, 수용성율 및 수분율은 23.34MPa, 13.86%, 76.73g/(min· m2) 및 0.11%입니다. 알루미나 분말의 적절한 함량은 KCl 입자의 크기를 미세화하고 더 조밀한 미세 조직을 얻을 수 있습니다. 마지막으로 최적화된 공정 매개변수를 사용하여 고강도 및 복잡한 구조의 복합 염심 부품을 제작했습니다.

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