Microstructure and Mechanical Properties of Permanent Mold Low-Pressure Casting and Sand Mold Gravity Casting of A357 Alloy

2014 ◽  
Vol 1004-1005 ◽  
pp. 1055-1061
Author(s):  
Qiang Li ◽  
Hai Jun Wu ◽  
Shao Ping Lu ◽  
Ling Jiao Kong ◽  
Qi Tang Hao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Low Pressure ◽  
Sand Mold ◽  
Pressure Casting ◽  
Permanent Mold ◽  
A357 Alloy ◽  
Gravity Casting ◽  
Low Pressure Casting

The microstructure and mechanical properties of permanent mold low-pressure casting (PMLPC) and sand mold gravity casting (SMGC) of A357 alloy were studied. The grain size of alloys formed by PMLPC is finer than that formed by sand mold gravity casting because of higher freezing rate of the former. The secondary dendrite arm spacing of PMLPC is approximately 15.2 μm (SD=4) while that of SMGC is 33.2 μm (SD=6). The ultimate tensile strength of PMLPC has a wider range from 350 MPa to 299.9 MPa and an elongation from 1.2 to 4.9. In comparison, the ultimate tensile strength of SMGC ranges from 307 MPa to 315 MPa and its elongation ranges from 2.1 to 3.7. These differences may be attributed to various factors, such as filling speed, filling pressure, and cooling rate, that affect the quality of permanent molds during the filling process.

scholarly journals Low-Pressure Casting of Aluminium AlSi7Mg03 (A356) in Sand and Permanent Molds

2020 ◽  
Vol 326 ◽  
pp. 06001
Author(s):  
Franco Chiesa ◽  
Bernard Duchesne ◽  
Gheorghe Marin
Keyword(s):  
Precipitation Hardening ◽  
Pressure Rise ◽  
Low Pressure ◽  
Magnesium Content ◽  
Pressure Casting ◽  
Gravity Casting ◽  
Hardening Treatment ◽  
Low Pressure Casting ◽  
Strength And Ductility ◽  
At Will

Aluminium A356 (AlSi7Mg03) is the most common foundry alloy poured in sand and permanent molds or lost-wax shells. Because of its magnesium content, this alloy responds to a precipitation hardening treatment. The strength and ductility combination of the alloy can be varied at will by changing the temper treatment that follows the solutionizing and quenching of the part. By feeding the mold from the bottom, the low-pressure process provides a tranquil filling of the cavity. A perfect control of the liquid metal stream is provided by programming the pressure rise applied on the melt surface. It compares favorably to the more common gravity casting where a turbulent filling is governed by the geometry of the gating system.

Effect of Heat Treatment on Microstructures and Mechanical Properties of A356 Alloy by Low Pressure Casting

2015 ◽  
Vol 1096 ◽  
pp. 319-324
Author(s):  
Xiao Jian Yu ◽  
Ya Lin Lu ◽  
Fu Xian Zhu ◽  
Xing Cheng Li
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Process ◽  
A356 Alloy ◽  
Low Pressure ◽  
Holding Time ◽  
Pressure Casting ◽  
Heat Treatment Process ◽  
Low Pressure Casting ◽  
Microstructures And Mechanical Properties

Automobile wheel of A356 alloy was cast by low pressure casting process. The effect of heat treatment process on microstructures and mechanical properties of A356 alloy cast was discussed. The results indicated that optimal parameters of heat treatment process for A356 alloy included solution temperature of 535°Cand holding time of 4.5hours, aging temperature of 145°Cand holding time of 4hours. Ultimate strength of A356 is 270MPa and elongation rate is 10%. Meanwhile, the microstructure has been apparently improved. The eutectic silicon particle became more spheroidal and distributed uniformly in matrix.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

scholarly journals Microstructure and Mechanical Properties of Dissimilar Friction Welding Ti-6Al-4V Alloy to Nitinol

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 109
Author(s):  
Ateekh Ur Rehman ◽  
Nagumothu Kishore Babu ◽  
Mahesh Kumar Talari ◽  
Yusuf Siraj Usmani ◽  
Hisham Al-Khalefah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flow Stress ◽  
Intermetallic Compound ◽  
Ultimate Tensile Strength ◽  
Friction Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Dissimilar Joints ◽  
Dissimilar Alloys

In the present study, a friction welding process was adopted to join dissimilar alloys of Ti-Al-4V to Nitinol. The effect of friction welding on the evolution of welded macro and microstructures and their hardnesses and tensile properties were studied and discussed in detail. The macrostructure of Ti-6Al-4V and Nitinol dissimilar joints revealed flash formation on the Ti-6Al-4V side due to a reduction in flow stress at high temperatures during friction welding. The optical microstructures revealed fine grains near the Ti-6Al-4V interface due to dynamic recrystallization and strain hardening effects. In contrast, the area nearer to the nitinol interface did not show any grain refinement. This study reveals that the formation of an intermetallic compound (Ti2Ni) at the weld interface resulted in poor ultimate tensile strength (UTS) and elongation values. All tensile specimens failed at the weld interface due to the formation of intermetallic compounds.

scholarly journals The Effect of Water Concentration in Ethyl Alcohol on the Environmentally Assisted Embrittlement of Austempered Ductile Irons

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 94
Author(s):  
Petar Janjatovic ◽  
Olivera Eric Cekic ◽  
Leposava Sidjanin ◽  
Sebastian Balos ◽  
Miroslav Dramicanin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Iron ◽  
Ultimate Tensile Strength ◽  
Ethyl Alcohol ◽  
Water Concentration ◽  
Different Types ◽  
Influence Of Water ◽  
Iron Material ◽  
Proof Strength

Austempered ductile iron (ADI) is an advanced cast iron material that has a broad field of application and, among others, it is used in contact and for conveyance of fluids. However, it is noticed that in contact with some fluids, especially water, ADI material becomes brittle. The most significant decrease is established for the elongation. However, the influence of water and the cause of this phenomenon is still not fully understood. For that reason, in this paper, the influence of different water concentrations in ethyl alcohol on the mechanical properties of ADI materials was studied. The test was performed on two different types of ADI materials in 0.2, 4, 10, and 100 vol.% water concentration environments, and in dry condition. It was found that even the smallest concentration of water (0.2 vol.%) causes formation of the embrittled zone at fracture surface. However, not all mechanical properties were affected equally and not all water concentrations have been critical. The highest deterioration was established in the elongation, followed by the ultimate tensile strength, while the proof strength was affected least.

Sign in / Sign up

Export Citation Format

Share Document