WATER-SOLUBLE CORES – VERIFYING DEVELOPMENT TRENDS

January 2015
Materials and Technologies 49(1):61-67

Authors: Eliska Adamkova, Petr Jelinek, Jaroslav Beňo SAND TEAM spol.r.o., Frantisek Mikgovsky

Abstract

Application of pure inorganic salt-based cores has been known since the end of the 20th century, especially in the field of gravity and low-pressure die casting. The contemporary trend in technology leads to the use of the cores in the field of non-ferrous-alloy high-pressure die casting. The main methods of the core production include high-pressure squeezing and shooting (warm core box). During research processes it was shown that pure-salt application is not very suitable for high-pressure casting. That is why a composite salt-based matrix of defined properties was started to be used. The aim of the paper is to verify the influences of the chemical composition, shape and morphology of the grains of various NaCl compounds on the mechanical properties (the bending strength) of water-soluble salt cores used for Al-alloy high-pressure die casting and to evaluate their properties resulting from the squeezing and shooting methods.

Korea Abstract

순수 무기염 기반 코어의 적용은 20세기 말부터 특히 중력 및 저압 다이캐스팅 분야에서 알려져 왔습니다. 기술의 현대적 경향은 비철 합금 고압 다이캐스팅 분야에서 코어의 사용으로 이어집니다.

코어 생산의 주요 방법은 고압 압착 및 슈팅(웜 코어 박스)입니다. 연구 과정에서 순수 소금 적용은 고압 주조에 적합하지 않은 것으로 나타났습니다.

이것이 정의된 특성의 복합 염 기반 매트릭스가 사용되기 시작한 이유입니다. 이 논문의 목적은 Al-합금 고압 다이캐스팅에 사용되는 수용성 염심의 기계적 특성(굽힘 강도)에 대한 다양한 NaCl 화합물 입자의 화학적 조성, 모양 및 형태의 영향을 확인하는 것입니다. squeezing 과 shooting 방법으로 인한 특성을 평가합니다.

Table 2: Comparison of declared chemical compositions and EDX microanalysis of the investigated real compositions Tabela 2: Primerjava deklarirane kemijske sestave in EDX-mikroanaliza preiskovanih realnih sestav

Figure 4: Shattered surface of crushed-rock salts (samples Nos. 1, 2) and EDX analysis of its chemical composition Slika 4: Razbita povr{ina drobljene kamene soli (vzorca {t. 1 in 2) in EDX-analiza kemijske sestave

Figure 5: Regular cubic grains of Alpine salts (samples Nos. 3, 4) and EDX analysis confirming the presence of anticaking agents on the salt grain surface (MgCO3, CaCO3) Slika 5: Pravilna kockasta zrna soli Alpine (vzorca {t. 3 in 4) in EDX-analiza, ki potrjuje prisotnost sredstva proti sprijemanju na povr{ini zrn soli (MgCO3, CaCO3)

Figure 6: Oval form of sea-salt grains (sample No. 5) and EDX analysis of its chemical composition Slika 6: Ovalna oblika zrn morske soli (vzorec {t. 5) in EDX-analiza kemijske sestave

Figure 7: Regular dipyramidal form of NaCl, p. a. – standard (sample No. 7) and EDX analysis of its chemical composition Slika 7: Dvopiramidna pravilna oblika NaCl, p. a. – standard (vzorec {t. 7) in EDX-analiza kemijske sestave

Figure 8: Different hygroscopicity trends for squeezed and shot cores Slika 8: Razli~na usmeritev higroskopi~nosti iztisnjenega in vbrizganega jedra

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