Effect of Compound Modification on Microstructure and Properties of High Silicon Aluminum Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 114-117 ◽  
Author(s):  
Niu Can Liu ◽  
Guang Sheng Kang ◽  
Zhong Xia Liu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Rare Earth ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Unmodified Alloy ◽  
Microstructure And Properties ◽  
Compound Modification ◽  
Double Modification

Double compound modification was carried out for hypereutectic Al-24Si alloy. The experiment showed that double modification with phosphorus and rare earth can fine the microstructure of alloy. The complex modifications of phosphorus and rare earth make the coarse block primary silicon obviously refined and the large needle eutectic silicon modified to the fine fibrous or lamella ones. The alloys with the additions of 0.10% P(phosphorus) and 0.90% RE(rare earth) have the optimal microstructure and the highest mechanical properties. Compared with the unmodified alloy, the primary silicon of alloys can be refined from 93.5μm to 24.1μm. The tensile strength is improved from 248MPa to 305MPa and the elongation is improved from 0.31% to 0.47%. Mechanism of double compound modification with phosphorus and rare earth is discussed as well.

Effect of Compound Modification on Structure of Hypereutectic Al-Si Alloy

2010 ◽  
Vol 160-162 ◽  
pp. 189-193
Author(s):  
Niu Can Liu ◽  
Jun Qing Li ◽  
Zhong Xia Liu
Keyword(s):  
Rare Earth ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Unmodified Alloy ◽  
Modification Effect ◽  
Compound Modification ◽  
Structure Of Alloy ◽  
Double Modification

Double compound modification was carried out for hypereutectic Al-24Si alloy. The experiment showed that double modification with phosphorus and rare earth can fine the structure of alloy. The complex modifications of phosphorus and rare earth make the coarse block primary silicon obviously refined and the large needle eutectic silicon modified to the fine fibrous or lamella ones. Phosphorus mainly refines the primary silicon. Rare earth can well refine the primary and eutectic silicon, but its modification effect on the eutectic silicon is more obvious. The alloys with the additions of 0.10% phosphorus and 0.9% rare earth have the optimal microstructure. Compared with the unmodified alloy, the primary silicon of alloys can be refined from 93.5 μm to 24.1 μm and the eutectic silicon can be refined from 8.5 μm to 5.3 μm. Mechanism of double compound modification with phosphorus and rare earth is discussed as well.

The Influence of the Al-Ti-B/Al-Sr Modification on the Microstructure and Properties of the Hypereutectic Al-Si Alloy in Automotive Piston

2013 ◽  
Vol 744 ◽  
pp. 339-344 ◽  
Author(s):  
Meng Xiang Liu ◽  
Jian Mei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction And Wear ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Optical Microscope ◽  
Sr Modification ◽  
Alloy Microstructure ◽  
Compound Modification ◽  
Better Than

By using some types of means such as Optical Microscope (OM), Scanning Electron Microscopy(SEM), the testing of tensile mechanical properties and the testing of friction and wear, the impacts of the Al-5Ti-1B and Al-20Sr modification on the Al-16Si-4Cu-0.5Mg-0.2Mn alloy microstructure, mechanical properties and friction properties are researched. The results turn out that the modification can significantly refine the primary silicon and the eutectic silicon in the alloy, the Al-5Ti-1B mainly refined the primary silicon in the alloy, the Al-20Sr refined the eutectic silicon; the alloy’s effect of refinement after compound modification is better than that in separate metamorphism. Modification can improve the tensile strength and elongation of the alloy: the tensile strength of the alloy has been increased by 65MPa after its compound modification; also the elongation by 0.4%. Modification can improve wear-resisting property of the alloy and also its effect of compound modification is better than that of separate metamorphism. The modification mechanism of Al-5Ti-1B is that Al3Ti and TiB2 belongs to heterogeneous nucleation; while the modification mechanism of Al-20Sr is that the strontium changes the growth pattern of Si phase.

Effect of Sr on the Microstructure and Properties of Hypereutectic Al-20 wt% Si Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 454-459 ◽  
Author(s):  
Xiao Song Li ◽  
An Hui Cai ◽  
Gang Liu ◽  
Yong Zhou ◽  
Ji Jie Zeng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Columnar Dendrite ◽  
Large Plate ◽  
Microstructure And Properties ◽  
Small Block ◽  
Microstructures And Mechanical Properties ◽  
Morphology And Mechanical Properties

The effect of Sr on the microstructures and mechanical properties of Al-20 wt% Si alloys were investigated. The results show that with increasing of the Sr content, the primary silicon firstly changes from polygonal block or large plate to small block, then to large polygonal block, and a large number of honeycomb-like on the primary silicon block. The eutectic silicon firstly changes into a fine start with a long needle-like fibrous or branched further to a short stubby dendrite or worm-like, continuously columnar dendrite α of quantity increase. In addition, with increasing the Sr content, the elongation of alloy increases, but there are ups and downs, the tensile strength changes little after the first sharp increases in hardness is parabola. When the Sr content is between 0.04 wt% and 0.06 wt%, the morphology and mechanical properties is the most ideal.

Effect of Sr + RE Combination Modifier on Microstructure and Mechanical Properties of Al-40 Wt％ Si Alloy

2011 ◽  
Vol 194-196 ◽  
pp. 1296-1300
Author(s):  
Xiao Song Li ◽  
Wei Hu ◽  
An Hui Cai ◽  
Hua Chen ◽  
Yong Zhou
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Uniform Distribution ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Large Plate ◽  
Small Block ◽  
Microstructure And Mechanical Properties

The effect of the Sr + RE complex modifications on microstructure and mechanical properties of Al-40 wt% Si alloy were investigated. The results show that Sr + RE complex modification not only on primary silicon and eutectic silicon with modification, but also on dendrite α significantly refine. When the addition of RE remain unchanged, with increasing of the addition of Sr, the primary silicon firstly changes from polygonal block or large plate to small block, then to large polygonal block, edge and corner passivations. The eutectic silicon firstly changes into a fine start with a long needle-like fibrous or branched further to a short stubby dendrite or worm-like, The eutectic silicon changes from needle to a fibrous sheet plus short rod, then to short rod end for the dense, or even granular. The dendrite α changes from highly developed dendritic to equiaxed and uniform distribution. In addition, with increasing of the addition of Sr, the mechanical properties has been significantly improved, tensile strength increased by 37%, elongation is more than double, the hardness increased by 21%. When the Sr addition is between 0.05 wt% and 0.077 wt%, the microstructure and mechanical properties are the best.

scholarly journals Optimizing the Microstructure and Mechanical Properties of Vacuum Counter-Pressure Casting ZL114A Aluminum Alloy via Ultrasonic Treatment

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4232
Author(s):  
Gang Lu ◽  
Pengpeng Huang ◽  
Qingsong Yan ◽  
Pian Xu ◽  
Fei Pan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Ultrasonic Treatment ◽  
Eutectic Silicon ◽  
Primary Phase ◽  
Pressure Casting ◽  
Counter Pressure ◽  
Casting Aluminum Alloy ◽  
Casting Aluminum

The effect of ultrasonic temperature on density, microstructure and mechanical properties of vacuum counter-pressure casting ZL114A alloy during solidification was investigated by optical microscopy (OM), scanning electron microscope (SEM) and a tensile test. The results show that compared with the traditional vacuum counter-pressure casting aluminum alloy, the primary phase and eutectic silicon of the alloy with ultrasonic treatment has been greatly refined due to the dendrites broken by ultrasonic vibration. However, the refining effect of ultrasonic treatment on vacuum counter-pressure casting aluminum alloy will be significantly affected by ultrasonic temperature. When the ultrasonic temperature increases from 680 °C to 720 °C, the primary phase is gradually refined, and the morphology of eutectic silicon also changes from coarse needle-like flakes to fine short rods. With a further increase in the ultrasonic temperature, the microstructure will coarse again. The tensile strength and elongation of vacuum counter-pressure casting ZL114A alloy increases first and then decreases with the increase of ultrasonic temperature. The optimal mechanical properties were achieved with tensile strength of 327 MPa and the elongation of 5.57% at ultrasonic temperature of 720 °C, which is 6.3% and 8.2%, respectively, higher than that of alloy without ultrasonic treatment.

Effect of Compound Modification and Cooling Rate on Microstructure and Mechanical Properties of Al-25%Si Alloy

2016 ◽  
Vol 877 ◽  
pp. 27-32
Author(s):  
Hai Tao Zhang ◽  
Dong Tao Wang ◽  
Ke Qin ◽  
Xing Han ◽  
Bo Shao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Mechanical Testing ◽  
Rate Increase ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Microstructure And Mechanical Properties ◽  
Phosphorus Modification ◽  
Compound Modification

The effect of phosphorus on primary silicon, phosphorus and mischmetal (Ce-50La) modification on primary and eutectic silicon and cooling rate on microstructure of Al-25%Si are investigated. The results show that, with the addition of phosphorus, the size of primary silicon decreases from 93.6μm to 24.75μm. The morphology of primary silicon changes from irregular to polygonal. When Al-25%Si is modified by phosphorus and mischmetal, primary and eutectic silicon all change effectively. Addition of mischmetal on the basis of phosphorus modification have no influence to primary silicon, but it can make morphology of eutectic silicon change from lamellar to short rod-like when the content of mischmetal reaches 0.5%. The cooling rate curves show the change of temperature in different height of wedge-shaped mould. When cooling rate increases, microstructure of Al-25%Si refines, the size of primary silicon decrease to 22.7μm. The results obtained from mechanical testing demonstrate that the addition of mischmetal and increasing of cooling rate increase hardness value of Al-25%Si alloy.

Effects of Mixed RE on Die-Casting Microstructures and Properties of Commercial Mg Alloy

2011 ◽  
Vol 295-297 ◽  
pp. 974-977
Author(s):  
Yao Li ◽  
Jun Jie Yang ◽  
Wu Xin Yu ◽  
Ping Xue ◽  
Zhi Jiang Zuo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Rare Earth ◽  
Die Casting ◽  
Mg Alloy ◽  
Crystal Boundary ◽  
Microstructure And Properties ◽  
Reticular Structure

In this paper, the commercial AZ91 Mg alloy with mixed rare earth (RE) Y、Gd and Nd has been investigated and effects of RE on die-casting microstructure and properties of die-casting Mg alloy has been also explored. The results indicate that RE can effectively refine the grain size of the alloy and improve inner microstructures transforming the reticular structure of Mg17Al12phrase into granular or dotlike structure. At the same time, the amount of the compound at crystal boundary is less than that in the alloy without RE. In addition, the mechanical properties of AZ91 Mg alloy with mixed RE has been improved efficiently, and its tensile strength sbcan reach over 260MPa; its elongation δ can also reach over 4.5％. When the amount of mixed RE exceeds 5%, it will form coarse Al-RE compounds, which can low the mechanical properties of Mg alloy.

scholarly journals EFFECT OF Sr ADDITION ON THE MICROSTRUCTURE AND PROPERTIES OF THE A356 Al ALLOY

2021 ◽  
Vol 55 (3) ◽  
Author(s):  
Wenduan Yan ◽  
Gaosheng Fu ◽  
Yanhua Xu ◽  
Wanqing Lai ◽  
Hongling Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Removal Rate ◽  
Eutectic Silicon ◽  
Al Alloy ◽  
Inclusion Removal ◽  
Microstructure And Properties ◽  
Comprehensive Properties ◽  
High Purification

An effective way of integrating purification and modification is used for casting the A356 Al alloy. Self-generated inclusion-eliminating flux exhibits excellent purification in the alloy with an inclusion-removal rate of 74 %. The grains of eutectic silicon are fine or vermicular, and diffusely distributed in the A356 Al alloy at a 0.012 w/% Sr addition. The mechanical properties of the alloy are significantly improved, including a tensile strength of 208.5 MPa and an elongation of 17.5 %. As the Sr addition is increased, the comprehensive properties of the material are not improved. The Sr addition can be reduced to a certain degree during the modification of the melt after high purification. The addition of 0.012 w/% Sr is most preferable in the alloy.

The Effect of RE on the Microstructure and Properties of Weld of 7075 Aluminum Alloy

2013 ◽  
Vol 456 ◽  
pp. 521-524
Author(s):  
Lian Jie Li ◽  
Xu Ren Huang ◽  
Hua Kai Wei
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Mechanical Performance ◽  
Control Group ◽  
Optimal Dosage ◽  
7075 Aluminum Alloy ◽  
Microstructure And Properties ◽  
The Rare Earth

In this paper 7075 aluminum alloy is studied as the object, through adding different percentages of the rare earth elements expecting to optimize alloy formula and find the optimal dosage of rare earth in order to improve the microstructure and properties of weld. The results show that when the rare earth content reaches 0.3%, alloys tensile strength comes to 388.39 MPa, and extensibility 18.22%. Compared with the control group, tensile strength is increased about 8.4%, extensibility about 14.7%, and the integrative mechanical performance is optimal. Metallographic research shows that accession of rare earth elements have perfect refinement effect to the microstructure of 7075 aluminum alloy and can improve the quality of weld.

Effects of Different Cooling Rate and Modifiers on the Microstructures of 4Y32 Aluminum Alloy

2009 ◽  
Vol 79-82 ◽  
pp. 1911-1914
Author(s):  
Gao Song Wang ◽  
Yu Bo Zuo ◽  
Zhi Hao Zhao ◽  
Jian Zhong Cui
Keyword(s):  
Aluminum Alloy ◽  
Cooling Rate ◽  
Master Alloy ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
Slow Cooling ◽  
Master Alloys ◽  
Additional Amount ◽  
Compound Modification ◽  
Addition Amount

This paper discussed the effects of different cooling rate on the microstructure of the 4Y32 aluminum alloy and the refinement and modification on 4Y32 aluminum alloy by using Na and Al-10%Sr master alloys in various treatment states. And also the effect of Al-10Sr and Al-3Ti-1B compound modification on microstructures of 4Y32 aluminum alloy has also been studied. The results showed that: the primary silicon was eliminated during slow cooling. As the cooling rate increased, the number of primary silicon was also growing, but the size of primary silicon and eutectic silicon were significantly refined; when without modification, the shape of eutectic silicon was needle and flake; 4Y32 aluminum alloy could be effectively refined after Na modification, under the optimum addition amount of 0.8wt%. The best modification was achieved with 15 minutes, that is, the shape of primary silicon changed to small granular or oval and the primary silicon was eliminated; the as-cast structure has been improved after Al-10Sr modification, under the optimum addition amount of 0.2wt. %, the shape of eutectic silicon changed to fine short rod or point and the primary silicon was eliminated; However, in the compound modification, efficiency of Sr was decreased with the increasing additional amount of AI-3Ti-1B master alloy, which was attribute to the interaction of Sr and Ti.

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