Microstructure and Mechanical Properties of Hypereutectic Al-Si Alloy with 2% Fe Prepared by Semi-Solid Process

2012 ◽  
Vol 192-193 ◽  
pp. 130-135
Author(s):  
Shu Sen Wu ◽  
Chong Lin ◽  
Shu Lin Lü ◽  
Ping An
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Casting Process ◽  
Primary Si ◽  
Microstructure And Mechanical Properties ◽  
Combined Use ◽  
Average Grain Size ◽  
Semi Solid ◽  
3Si2 Phase ◽  
P Addition

The microstructure and mechanical properties of Al-17Si-2Fe-2Cu-1Ni (mass fraction, %) alloys with 0.4% or 0.8% Mn produced by semi-solid casting process were studied. The semi-solid slurry of the alloys was prepared by ultrasonic vibration (USV) process. With USV process, the average grain size of primary Si in the alloys could be refined to 21~24μm, whether with or without P modification. The P addition has no further refinement effect on the primary Si in the case of the combined use of USV with P addition. Without USV, the alloys contain a large amount of long needle-like β-Al5(Fe,Mn)Si phase and plate-like δ-Al4(Fe,Mn)Si2 phase. Besides, the alloy with 0.8% Mn contains a small amount of coarse dendritic α-Al15(Fe,Mn)3Si2 phase. With USV treatment and semi-solid casting process, the Fe-containing compounds in the alloys are refined and exist mainly as δ-Al4(Fe,Mn)Si2 particles with average grain size of about 18μm, and only a small amount of β-Al5(Fe,Mn)Si phase is remained. With USV treatment and without P modification, the ultimate tensile strengths (UTS) of the alloys containing 0.4% and 0.8%Mn produced by semi-solid process are 260MPa and 270MPa respectively at room temperature, and the UTS are 127MPa and 132MPa at 350°C.

Microstructure and Mechanical Properties of Mg-6Zn-1.4Y Alloy Produced by Rheo-Squeeze Casting Process

2016 ◽  
Vol 879 ◽  
pp. 530-535
Author(s):  
Xiao Gang Fang ◽  
Shu Sen Wu ◽  
Shu Lin Lü
Keyword(s):  
Mechanical Properties ◽  
Power Density ◽  
Squeeze Casting ◽  
Casting Process ◽  
Acoustic Power ◽  
Icosahedral Quasicrystal ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Grain Size And Shape ◽  
Semi Solid

Mg-Zn-Y alloys containing a thermally stable icosahedral quasicrystal phase (I-phase) will have wide application future on condition that primary α-Mg dendrite and the I-phase can be refined during the casting process. In this research, the microstructure and mechanical properties of the rheo-squeeze casting (RSC) Mg-6Zn-1.4Y alloys have been investigated. The Mg alloy melt was exposed to ultrasonic vibration (USV) with different acoustic power densities from 0 W/mL to 9 W/mL, and then the slurry was formed by squeeze casting. The results show that good semi-solid slurry with fine and spherical α-Mg particles could be obtained with the acoustic power density of 6 W/mL, and the average grain size and shape factor of primary α-Mg were 32 μm and 0.76, respectively. Meanwhile the coarse eutectic I-phase (Mg3Zn6Y) was refined obviously and dispersed uniformly. Compared with the samples without USV, the tensile strength and elongation of the RSC casting samples with 6 W/mL acoustic power density were elevated by 10.6% and 55.5%, respectively.

Comparison of Microstructure and Mechanical Properties of Semi-Solid Castings Produced Using Billets Made by EMS and SEED

2014 ◽  
Vol 217-218 ◽  
pp. 332-339 ◽  
Author(s):  
Xiao Kang Liang ◽  
Da Quan Li ◽  
Pascal Côté ◽  
Stephen P. Midson ◽  
Qiang Zhu
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Dendritic Structure ◽  
Casting Process ◽  
Grain Structure ◽  
High Quality ◽  
Microstructure And Mechanical Properties ◽  
Grain Structures ◽  
Heat Treated ◽  
Semi Solid

The spheroidal grains in billets used for semi-solid casting are generally manufactured by electromagnetic stirring (EMS) during the casting process. This method however, is not economically applicable for small quantities of the thixo billets. Swirled Enthalpy Equilibration Device (SEED) has been developed as a rheocasting process, and the SEED process is of interest for developing new thixo alloys, as well as for optimizing the thixocasting processes for high quality components. The objective of this paper is to compare the microstructure and mechanical properties of aluminum alloy 319s billets and castings produced using EMS and SEED feed materials. The experimental results show that for as-cast billets made from SEED process, a well-developed spheroidal grain structure is distributed throughout the cross-section of the billet, while for as-cast EMS billets, the grain structure is inhomogeneous, i.e., a dendritic structure was present adjacent to the surface of the billet, while a uniform, spheroidal structure was present at the centre. After the thixocasting process, however, the both SEED and EMS billets have well-developed, spheroidal grain structures. Mechanical properties of thixocast and T61 heat treated components are comparable for the both SEED and EMS billets.

Effects of Pulsed Magnetic Field on the Microstructure and Mechanical Properties of Mg97Y2Zn1 Alloy

2014 ◽  
Vol 1004-1005 ◽  
pp. 123-126 ◽  
Author(s):  
Jian Yin ◽  
Xiu Jun Ma ◽  
Jun Ping Yao ◽  
Zhi Jian Zhou
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Grain Size ◽  
Volume Fraction ◽  
Pulsed Magnetic Field ◽  
Second Phase ◽  
Microstructure And Mechanical Properties ◽  
Magnetic Field Treatment ◽  
Semi Solid ◽  
Strength And Plasticity

Effect of pulsed magnetic field treatment on the microstructure and mechanical properties of Mg97Y2Zn1 alloy has been investigated. When the pulsed magnetic field is applied on the alloy in semi-solid state, the α-Mg was modified from developed dendrite to fine rosette, resulting in a refined solidification microstructure with the grain size decreased from 4 mm to 0.5 mm. The volume fraction of the second phase ( X phase) increased by about 10 %. The yield strength, fracture strength and plasticity were improved by 21 MPa, 38 MPa and 2.4 %, respectively. The improvement of mechanical properties was attributed to the refined grain size and increased volume fraction of X phase.

Influence of Annealing on the Microstructure and Mechanical Properties of Electrodeposited Nanocrystalline Nickel

2011 ◽  
Vol 683 ◽  
pp. 103-112 ◽  
Author(s):  
B. Yang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Elastic Modulus ◽  
Grain Boundary ◽  
Boundary Structure ◽  
Boundary State ◽  
Microstructure And Mechanical Properties ◽  
Grain Boundary Structure ◽  
Average Grain Size ◽  
Different Grain Size

The evolution of the microstructure and mechanical properties of electrodeposited nanocrystalline Ni with different annealing procedures was studied systematically. For the annealed specimens hardness decreases with increasing average grain size but the dependence changes at different grain size ranges. The specimens annealed at a low temperature show higher hardness compared to the as-deposited nanocrystalline Ni, despite an increased measured average grain size. In association with this hardening an increase in elastic modulus and a decrease in microstrain was observed after annealing. With increasing annealing temperature both the tensile strength and the fracture strain were observed to decrease, this is companied with a transition from ductile to brittle in the fracture surfaces. These results indicated that the mechanical behaviour of nanocrystalline Ni depends not only on the average grain size but also on the grain boundary structure. A change in the grain boundary state arising from annealing may be responsible for the observed increase in hardness and elastic modulus as well as the deterioration of tensile properties.

Effect of Bi on Microstructure and Mechanical Properties of Extruded AZ80-2Sn Magnesium Alloy

2018 ◽  
Vol 37 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Hansong Xue ◽  
Xinyu Li ◽  
Weina Zhang ◽  
Zhihui Xing ◽  
Jinsong Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

AbstractThe effects of Bi on the microstructure and mechanical properties of AZ80-2Sn alloy were investigated. The results show that the addition of Bi within the as-cast AZ80-2Sn alloy promotes the formation of Mg3Bi2 phase, which can refine the grains and make the eutectic phases discontinuous. The addition of 0.5 % Bi within the as-extruded AZ80-2Sn alloy, the average grain size decreases to 12 μm and the fine granular Mg17Al12 and Mg3Bi2 phases are dispersed in the α-Mg matrix. With an increase in Bi content, the Mg17Al12 and Mg3Bi2 phases become coarsened and the grain size increases. The as-extruded AZ80-2Sn-0.5 %Bi alloy has the optimal properties, and the ultimate tensile strength, yield strength and elongation are 379.6 MPa, 247.1 MPa and 14.8 %, respectively.

Investigation of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Ni Base Superalloy

2012 ◽  
Vol 724 ◽  
pp. 481-485
Author(s):  
Kuk Hyun Song ◽  
Kazuhiro Nakata
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Base Material ◽  
Lap Joints ◽  
Stir Zone ◽  
Inconel 600 ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

This study evaluated the microstructure and mechanical properties of friction stir welded lap joints. Inconel 600 and SS 400 as experimental materials were selected, and friction stir welding was carried out at tool rotation speed of 200 rpm and welding speed of 100 mm/min. Applying the friction stir welding was notably effective to reduce the grain size of the stir zone, as a result, the average grain size of Inconel 600 was reduced from 20 μm in the base material to 8.5 μm in the stir zone. Joint interface between Inconel 600 and SS 400 showed a sound weld without voids and cracks. Also, the hook, along the Inconel 600 alloy from SS 400, was formed at advancing side, which directly affected an increase in peel strength. In this study, we systematically discussed the evolution on microstructure and mechanical properties of friction stir lap jointed Inconel 600 and SS 400.

scholarly journals Effect of Sc on the Hot Cracking Properties of 7xxx Aluminum Alloy and the Microstructure of Squeeze Castings

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6881
Author(s):  
Yongtao Xu ◽  
Zhifeng Zhang ◽  
Zhihua Gao ◽  
Yuelong Bai ◽  
Purui Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminum Alloy ◽  
Performance Test ◽  
Casting Process ◽  
Hot Cracking ◽  
Hot Tearing ◽  
Average Grain Size ◽  
Cylindrical Parts ◽  
Series Aluminum Alloy

In this paper, the effect of adding the refiner Sc to the high Zn/Mg ratio 7xxx series aluminum alloy melt on the hot tearing performance, microstructure, and mechanical properties of the alloy is studied. The hot tearing performance test (CRC) method is used to evaluate the hot tearing performance of the alloy. The squeeze casting process was used to form solid cylindrical parts to analyze the structure and properties of the alloy. This study shows that the hot cracking sensitivity of the alloy after the addition of the refiner Sc is significantly reduced. The ingot grain size is significantly reduced, and the average grain size is reduced from about 86 μm to about 53 μm. While the mechanical properties are significantly improved, and the tensile strength reduced from 552 MPa is increased to 571 MPa, and the elongation rate is increased from 11% to 14%.

Effects of Sr and B addition on microstructure and mechanical properties of AZ91 magnesium alloy

2007 ◽  
Vol 22 (9) ◽  
pp. 2423-2428 ◽  
Author(s):  
H.L. Zhao ◽  
S.K. Guan ◽  
F.Y. Zheng
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Solidification Range ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
B Additions ◽  
Az91 Magnesium

The effects of Sr and B addition on the microstructure and mechanical properties of AZ91 alloy were studied. The results of this work show that a small amount of Sr addition to AZ91 refined the grain size. The highest tensile strength was obtained from the alloy with the optimal composition of 0.5% Sr and 0.09% B added, in which the average grain size was 42 μm. The tensile strength and elongation of the AZ91–0.5%Sr–0.09%B alloy were 151 MPa and 1.62%, respectively. Some needle-shaped Al4Sr particles distributed mainly at grain boundaries have been observed in the alloys with Sr and B additions. The fluidity is improved significantly, and the solidification range decreased by adding Sr and B. The liquidus of AZ91 alloy decreased markedly with the addition of Sr and B, but the solidus hardly changed. Therefore, the solidification range can be decreased, which will improve the die-casting properties.

Synergetic Effect of ECAP and Friction Stir Welding on Microstructure and Mechanical Properties of Aluminium Sheets

2010 ◽  
Vol 667-669 ◽  
pp. 505-510
Author(s):  
Ilya Nikulin ◽  
Alla Kipelova ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Base Metal ◽  
Synergetic Effect ◽  
Aluminum Matrix ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Friction stir welding (FSW) was used to join the submicrocrystalline (SMC) grained Al-Cu-Mg-Ag sheets produced by equal channel angular pressing (ECAP) followed by hot rolling (HR). The effect of SPD and FSW on the microstructure and mechanical properties in the zone of base metal, as well as in the stirred zone (SZ) were examined. In addition, effect of standard heat treatment on microstructure and mechanical properties in these zones was considered. A refined microstructure with an average grain size of ~ 0.6 m and a portion of high-angle grain boundaries (HAGBs) of ~0.67 was produced in sheets by ECAP followed by HR at 250°C. The microcrystalline grained structure with average grain size of ~2.3 mm was found in joint weld. The moderate mechanical properties were revealed in SMC sheets and joint welds. Heat treatment considerably increases strength of the base metal as well as the joint welds. The higher strength of the alloy after T6 temper is attributed to the dense precipitations of  dispersoids having plate-like shape which are uniformly distributed within aluminum matrix. It was observed that FSW can produce full strength weld both in the tempered and in the un-tempered conditions.

Effects of Thermo-Mechanical Process on the Microstructure and Mechanical Properties of Low Carbon HSLA Steels

2006 ◽  
Vol 15-17 ◽  
pp. 786-791 ◽  
Author(s):  
J.S. Kang ◽  
Y. Huang ◽  
C.W. Lee ◽  
Chan Gyung Park
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cooling Rate ◽  
High Strength ◽  
Nucleation Site ◽  
Polygonal Ferrite ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Effects of deformation at austenite region and cooling rate on the microstructure and mechanical properties of low carbon (0.06 wt. % C) high strength low alloy steels have been investigated. Average grain size decreased and polygonal ferrite transformation promoted with increasing deformation amount at austenite region due to increase of ferrite nucleation site. Microstructure was also influenced by cooling rate resulting in the development of a mixture of fine polygonal ferrite and acicular ferrite at 10°C/s cooling rate. Discontinuous yielding occurred in highly deformed specimen due to the formation of polygonal ferrite. However, small grain size of highly deformed specimen caused lower ductile-to-brittle transition temperature than slightly deformed specimen.

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