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 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.

Forming Behaviour of Al-TiC In Situ Composites

2013 ◽  
Vol 765 ◽  
pp. 418-422 ◽  
Author(s):  
Ram Naresh Rai ◽  
A.K. Prasada Rao ◽  
G.L. Dutta ◽  
M. Chakraborty
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Uniform Distribution ◽  
Interface Bonding ◽  
Microstructure And Mechanical Properties ◽  
Micron Size ◽  
Forming Behaviour ◽  
Al Matrix

The forming behaviour of in-situ Al-TiC composites was investigated by comparing microstructure and mechanical properties of as-cast, forged and rolled specimens. The microstructures of forged and rolled specimens reveal uniform distribution of the TiC particles, which are responsible for the enhancement of the tensile strength of the composite. The formed samples were found to be crack free. This feature is very likely to be due to good interface bonding of uniformly dispersed sub-micron size TiC particles with the Al matrix.

Influence of Stirring Time and Holding Time on Microstructure and Properties of the A356 Alloy Modified by Sc

2013 ◽  
Vol 750-752 ◽  
pp. 687-690 ◽  
Author(s):  
Su Zhang ◽  
Gang Yang ◽  
Jian Hong Yi ◽  
Hong Yan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundary ◽  
Eutectic Silicon ◽  
A356 Alloy ◽  
Holding Time ◽  
Test Results ◽  
Modification Effect ◽  
Microstructure And Mechanical Properties ◽  
Stirring Time

Effects of the holding time and the stirring time on the microstructure and mechanical properties of A356 alloy modified by Sc are researched. According to the test results, most of the eutectic silicon phases have changed to the shape of creeping point, dispersed in the grain boundary of α (Al) phase while stirring 1 minute, in which case both the tensile strength and elongation reach the highest, resulting in the best modification effect. The results also indicate that microstructure and mechanical properties of the alloy reach are the best modification effect when the melt is held 15 minute. It can be known that the optimal stirring time is 1 minute and the optimal holding time is 15 minute in the experiment condition of the work.

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 Strontium on Structure and Property of ZL102

2013 ◽  
Vol 442 ◽  
pp. 40-43
Author(s):  
Jie Wang ◽  
Guo Sheng Cai ◽  
Hai Feng Lu ◽  
Yue Hong Jiang ◽  
Rong Fa Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Eutectic Silicon ◽  
Structure And Property ◽  
Sr Modification ◽  
Analysis Tools ◽  
Microstructure And Mechanical Properties ◽  
Fine Fiber

Analysis tools of microstructure and mechanical properties were used to study ZL102 that was modified by Sr and without modification. The experiment shows that the morphology of eutectic silicon and α-Al phase of the modified alloy have greater changes than that without modification. With the added amount of Sr increases, the morphology of the eutectic silicon changes from sheet into flakiness and fibrous, and finally the fine fiber; α-Al phase increased and showed a small short rod distribution. The optimized technology of Sr modification agent is 0.05%Sr addition, the tensile strength of modified alloy is 218.5 MPa, and the elongation is 2.8%.

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.

Effect of Liquid-Die-Forging Pressure on Microstructure and Mechanical Properties of A390 Sloping Swash-Plate

2012 ◽  
Vol 538-541 ◽  
pp. 1356-1359
Author(s):  
Guang An Zhang ◽  
Feng Jiang ◽  
Qi Zhou ◽  
Fu Fa Wu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Eutectic Silicon ◽  
Applied Pressure ◽  
Primary Silicon ◽  
Specific Pressure ◽  
Die Forging ◽  
Microstructure And Mechanical Properties ◽  
Swash Plate ◽  
Preheating Temperature

The effect of liquid-die-forging pressure on the microstructure and mechanical properties of A390 sloping swash-plate forming was investigated. It was found that the microstructure and comprehensive mechanical properties of the alloy were effectively improved by the liquid-die-forging pressure applied on the A390 aluminum melt. With continuous increasing of the specific pressure, the grain size of primary silicon gradually decreased, the fraction of eutectic silicon obviously decreased, and its morphology was granular mainly. When the applied pressure was 181 MPa, the size of primary silicon was reduced to about 20 μm. When the casting temperature of the alloy was 820 °C, the mould preheating temperature was 240 °C and the forging casting specific pressure reached 181 MPa, the sloping swash plate without macro-defects, and with the internal compact-gain structure and excellent mechanical properties can be obtained.

scholarly journals Effect of Sr and Sb Modification on the Microstructure and Mechanical Properties of 226 Silumin Pressure Casts

2015 ◽  
Vol 15 (1) ◽  
pp. 105-108 ◽  
Author(s):  
T. Szymczak ◽  
G. Gumienny ◽  
T. Pacyniak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Eutectic Silicon ◽  
Proof Stress ◽  
Sr Modification ◽  
Microstructure And Mechanical Properties

Abstract The work presents the effect of strontium and antimony modification on the microstructure and mechanical properties of 226 silumin casts. The performed research demonstrated that strontium causes high refinement of silicon precipitations in the eutectic present in the microstructure of the examined silumin and it significantly affects the morphology of eutectic silicon from the lamellar to the fibrous one. Sr modification also causes an increase of: the tensile strength „Rm” by 12%; the proof stress „Rp0,2” by 5%; the unit elongation „A” by 36% and the hardness HB by 13%. Antimony did not cause a change in the microstructure of the silumin, yet it caused an increase in Rm and HB by 5%, in Rp0,2 by 7% and in A by 4%.

Effect of Heat Treatment on Microstructure and Mechanical Properties of A390 Alloy

2013 ◽  
Vol 652-654 ◽  
pp. 1049-1053 ◽  
Author(s):  
Bao Li ◽  
Zhi Feng Zhang ◽  
Zhi Gang Wang ◽  
Jun Xu ◽  
Qiang Zhu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Primary Silicon ◽  
Lamellar Morphology ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated ◽  
Sharp Edges ◽  
A390 Alloy

In the present work, the effects of heat treatment on microstructure and mechanical properties of A390 alloy were investigated. The results show that the as-cast microstructure of A390 alloy mainly consists of primary silicon, α-Al, eutectic silicon and Al2Cu phase. The morphology of primary silicon is irregular polygonal block with sharp edges. Eutectic silicon exhibits a coarse plate-like and acicular morphology and the fishbone like Al2Cu phases are gathered at the grain boundary. During solution treatment, eutectic silicon undergoes fragmentation and spheroidization and T6 heat treatment has a profound effect on the dissolution of Cu and Mg. However, the morphology and size of primary silicon changes little. After the aging process, Al2Cu phases are precipited as lamellar morphology. As a result, the mechanical properties the heat treated A390 alloy increases significantly after T6 treatment.

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.

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