Modifying Effect of Al-Ti-C-P Master Alloy on Hypereutectic Al-Si Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 947-952
Author(s):  
Chun Xiang Xu ◽  
Li Ping Liang ◽  
Bin Feng Lu ◽  
Yong Jun Xue ◽  
Jin Shan Zhang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Master Alloy ◽  
Eutectic Silicon ◽  
Primary Silicon ◽  
X Ray Diffraction ◽  
Phase Constituent ◽  
Elevated Temperature Tensile ◽  
Average Grain Size ◽  
Modifying Effect ◽  
Alloy Microstructure

Al-Ti-C-P master alloy has been successfully fabricated by SHS-melting technology. Microstructures and phase constituent of Al-Ti-C-P master alloy were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and EDS. The results show that Al-Ti-C-P master alloy comprises TiAl3, TiC, AlP and α-Al matrix. After adding 2.0 wt% Al-Ti-C-P master alloy, microstructure and mechanical properties (after T6 treating) of ZL117 alloy has been improved dramatically: The average grain size of primary silicon decreases from 260 to 35 μm, edges and angles of primary silicon are passivated, the morphology of eutectic silicon changes from large needle-like one to fine rod-like or particle-like one, and the microstructures are noticeably refined; Room temperature tensile strength changes from 168 to 260 MPa while elevated temperature tensile strength (at 300) varies from 88 to 125 MPa. Impact toughness and macro-hardness(HB) increases to 17 J/cm2 and 97 from the original 6.5 J/cm2 and 92.

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 + 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.

Effect of Nd on Primary Silicon and Mechanical Properties of Hypereutectic Al-17.5%Si Alloy

2015 ◽  
Vol 1095 ◽  
pp. 111-114
Author(s):  
Wei Xi Shi ◽  
Cheng Wu Du ◽  
Bing Liu ◽  
Ping Yuan Wang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Primary Silicon ◽  
Maximum Tensile Strength ◽  
Average Grain Size ◽  
Nd Addition ◽  
Xrd Patterns ◽  
New Phase

The modification mechanism of hypereutectic Al-17.5%Si alloy with Nd was studied by OM and XRD. The results of OM analysis show that pure Nd could effectively refine primary in hypereutectic Al-17.5%Si alloy. When Nd addition is 0.3%, the average grain size of primary silicon reaches its minimum. The average grain size of primary silicon is reduced from 40~60μm to 10~30μm after modification. XRD patterns show that no new phase forms after Nd modification. The results of mechanical properties tests show that whole properties of modified samples are significantly improved. When Nd addition is 0.3%, tensile strength of the alloy reaches its maximum. Tensile strength is increased about 35.8% from 120 MPa to 163 MPa. Elongation was increased about 175% from 0.8% to 2.2%. The improvement of mechanical properties should attribute to fine primary after modification.

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.

scholarly journals The Study of the Tensile Strength of AlSi21CuNiMg Silumin in the Final Stage of Solidification and the Initial Stage of Cooling

2019 ◽  
Vol 3 (3) ◽  
pp. 57-61
Author(s):  
Remigiusz Romankiewicz
Keyword(s):  
Tensile Strength ◽  
Master Alloy ◽  
Primary Silicon ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Scanning Microscope ◽  
Alloy Structure ◽  
Initial Stage ◽  
Strength Tests ◽  
Solidification Stage

The paper presents the results of tensile strength tests of AlSi21CuNiMg silumin made on a test stand. Silumin was under examination in an unmodified state and after modification with AlCu19P1.4 master alloy in quantity of 0.2% in relation to the mass of the alloy. Using a scanning microscope, the surface fractures obtained from tensile tests were tested. The structure and profiles of fractures were examined using an optical microscope. Modification of the tested silumin resulted in a favorable fragmentation and regular distribution of the crystals of the primary silicon in the alloy structure, which led to an almost twofold increase in the strength of the silumin samples at the final solidification stage from 3.5 to 6.6 MPa. As a result of these changes, the resistance of silumin to hot cracks should increase, which is of great importance when casting hypereutectic silumin in a metal mould that strongly inhibits the shrinkage of the castings.

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.

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.

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

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.

Modification of Hypereutectic Al-20%Si Alloy by Neodymium

2015 ◽  
Vol 1095 ◽  
pp. 180-183
Author(s):  
Wei Xi Shi ◽  
Cheng Wu Du ◽  
Guang Zhe Lv ◽  
Chang Wan Liu
Keyword(s):  
Mechanical Properties ◽  
Trace Element ◽  
Base Metal ◽  
Eutectic Silicon ◽  
Trace Element Analysis ◽  
Primary Silicon ◽  
Sem Analysis ◽  
Silicon Phase ◽  
Element Analysis ◽  
Average Grain Size

The modification mechanism was studied by OM, SEM, XRD and Trace Element Analysis. The results of OM and SEM analysis show that pure Nd can effectively refine primary and eutectic silicon in hypereutectic Al-20%Si alloy. Morphology of primary silicon is transformed from pentalpha to block and the average grain size of primary silicon is reduced from 80~120μm to 20~50μm after modification. Trace Element Analysis results show that Nd can purity base metal and reduce impurity contents. XRD patterns show that no new phase formed after Nd modification. The results of mechanical properties test show that whole properties of modified sample are significantly improved. Tensile strength increases about 35.8% from 117 MPa to 148 MPa after modification, Elongation change increases about 193% from 0.56% to 1.64%. The improvement of mechanical properties should be attributed to fine primary Si phase and eutectic silicon phase and purification of base metal after modification.

Application Research of Al-Fe-P Master Alloy on Modifying ZL109 Alloys

2013 ◽  
Vol 750-752 ◽  
pp. 655-658
Author(s):  
Guang Hui Qi
Keyword(s):  
Mechanical Properties ◽  
Master Alloy ◽  
Application Research ◽  
Technological Parameters ◽  
Piston Alloy ◽  
Primary Si ◽  
Average Grain Size ◽  
Master Alloys ◽  
Modifying Effect

In order to settle the environmental pollution and improve the excellent rate of products, ZL109 piston alloy modified by Al9Fe3P master alloy was prepared in factory. The microstructures and mechanical properties of ZL109 piston alloy were invested respectively. The technological parameters and modifying effect of using Al9Fe3P alloy were researched too. Experiments show that high quality of ZL109 pistons can be produced by adding 0.4~0. 5wt% Al9Fe3P master alloy at 760-770°C.The maxim and average grain size of primary Si decrease largely, less than 66μm and 40μm respectively, and the mechanical properties were improved accordingly. It was proved that Al-Fe-P master alloys have advantages such as no pollution, no reaction slag, shorter modifying time and saving energy, which would reduce the total cost of piston products. So Al-Fe-P master alloy is a promising modifier to refine ZL109 piston alloys.

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