Thermal Analysis of Sr Modification Effect of ZL104 Alloy

This paper studied the relationship between the residual amount of Sr and the morphology of the eutectic Si phase in A356 obtained through different modification treatment processes; additionally, the cooling rates of molds were studied. The eutectic Si phase revealed a satisfactory modification effect at residual Sr amounts above 0.01 wt % in A356 alloys cast using an iron mould. Complete modification of the eutectic Si phase could be achieved at a Sr additive amount 0.03 wt % in an A356 melt. The addition of higher amounts of Sr (~0.04–0.06 wt %) did not improve the modification effect. With the addition of 0.06 wt % Sr into A356 alloy melt and holding at 750 °C, the anti-fading capacity of Sr modification effect could be sustained for 120 minutes. More Sr is needed to obtain a good modification of eutectic Si for an A356 alloy cast using a sand mold.

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Modification Effects of Sb on Al7SiMg Alloy Measured with Cooling Curve Analysis

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.2113 ◽

2016 ◽

Vol 879 ◽

pp. 2113-2118 ◽

Cited By ~ 1

Author(s):

Shu Sen Wu ◽

Meng Jie Lü ◽

Jian Xun Chen ◽

You Wu Mao ◽

Shu Lin Lü

Keyword(s):

Thermal Analysis ◽

Growth Temperature ◽

Curve Analysis ◽

Cooling Curve ◽

Eutectic Solidification ◽

Microstructure Observation ◽

Modification Effect ◽

Cooling Curve Analysis ◽

Computer Aided ◽

Eutectic Si

The modification mechanism of Sb on eutectic Si phase of Al-Si alloys was not understood very well. In this paper the modification effects of Sb on Al7SiMg alloy were investigated by computer aided cooling curve thermal analysis coupled with microstructure observation. The results show that the addition of Sb with 0.1%~0.25% amount has refining effect on eutectic Si phase, and this modification effect can be recorded by the cooling curve. The addition of Sb decreases the growth temperature of the eutectic solidification (TEG) by 5.0 °C to 7.8 °C, and this indicates that there is an undercooling effect with Sb modification. Moreover, faster cooling rate can obtain more superior morphology of eutectic Si, which can be changed from short rod to nearly granular particles. The morphology of eutectic Si is nearly unchanged with holding time extending from 0.5h to 2.5h, which means Sb has long modification effect for Al-Si alloys.

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The Effect of Sr Modification on the Microstructure and Properties of Mg2Si Reinforced Near-Eutectic Al-Si Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.638 ◽

2013 ◽

Vol 750-752 ◽

pp. 638-641

Author(s):

Yong Tian Liu ◽

Ji Xing Lin ◽

Xv Peng Wu ◽

Li Yuan Niu ◽

Guang Yu Li

Keyword(s):

Tensile Strength ◽

Master Alloy ◽

Eutectic Silicon ◽

Mg Alloy ◽

Microstructure And Properties ◽

Sr Modification ◽

Modification Effect ◽

Different Content

The effect of Al-10Sr master alloy modifier with different content on the microstructure and properties of as-cast Al-12.6Si-0.35 Mg alloy was investigated. The results show that, eutectic silicon varies from original needle and flake to fibrous shape; The shape, size, and quantity of α -Al all changed; When Sr content is 0.023%, the modification effect is most ideal, α -Al shows the highest quantity and smallest size. Meanwhile, the tensile strength and elongation of the alloy reach to the optimum values of 248.2 MPa and 7.2% respectively. These two values are 1.34 and 2.77 times higher than the 185 MPa and 2.6% before modification respectively.

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