scholarly journals A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 142
Author(s):  
Minghao Guo ◽  
Ming Sun ◽  
Junhui Huang ◽  
Song Pang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Grain Morphology ◽  
Strengthening Mechanism ◽  
Grain Structure ◽  
Sand Mold ◽  
Tensile Yield Strength ◽  
Fibrous Network ◽  
Eutectic Si ◽  
Microstructures And Mechanical Properties

Fabrication condition greatly influences the microstructures and properties of Al alloys. However, most of the available reports focus on a single fabrication technique, indicating there is still a lack of systematic comparisons among wider ranges of fabrication methods. In this paper, with conventional casting (via sand/Fe/Cu mold) and additive manufacturing (AM, via selective laser melting, SLM) methods, the effects of cooling rate (Ṫ) on the microstructures and mechanical properties of hypoeutectic Al-10Si-0.5Mg alloy are systematically investigated. The results show that with increasing cooling rate from sand-mold condition to SLM condition, the grain size (d) is continuously refined from ~3522 ± 668 μm to ~10 μm, and the grain morphology is gradually refined from coarse dendrites to a mixed grain structure composed of columnar plus fine grains (~10 μm). The eutectic Si particles are effectively refined from blocky shape under sand/Fe-mold conditions to needle-like under Cu-mold conditions, and finally to fine fibrous network under SLM condition. The tensile yield strength and elongation is greatly improved from 125 ± 5 MPa (sand-mold) to 262 ± 3 MPa (SLM) and from 0.8 ± 0.2% (sand-mold) to 4.0 ± 0.2% (SLM), respectively. The strengthening mechanism is discussed, which is mainly ascribed to the continuous refinement of grains and Si particles and an increase in super-saturation of Al matrix with increasing cooling rate.

Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

2016 ◽  
Vol 849 ◽  
pp. 570-579
Author(s):  
Qiang Huang ◽  
Jin Xia Song ◽  
Qing Li ◽  
Wei Peng Ren ◽  
Xin Guang Guan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Room Temperature ◽  
Rupture Life ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.

Effect of Sc on As-Cast Microstructures and Mechanical Properties of Al-Si-Mg-Cu-Ti Alloys

2017 ◽  
Vol 732 ◽  
pp. 32-37 ◽  
Author(s):  
Ming He Wang ◽  
Xiao Dong Du ◽  
Yu Kun Li ◽  
Zhen Zhang ◽  
Hai Lin Su ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Testing Machine ◽  
Ti Alloys ◽  
Universal Testing ◽  
Transmission Electron ◽  
Heat Treated ◽  
Eutectic Si ◽  
Microstructures And Mechanical Properties ◽  
Equiaxed Grain

The as-cast microstructures and mechanical properties of Al-Si-Mg-Cu-Ti alloys with and without Sc were investigated by metallographic microscope, field emission scanning electron microscope, energy spectrum analysis, transmission electron microscope and universal testing machine. The result shows that adding 0.20wt.% Sc into the casting alloy can refine the grain, change the growth morphology from dendrite to fine equiaxed grain, and the morphology of eutectic Si by rough laminar structure into fine fibrous. The tensile strength of alloy with 0.20wt.% Sc is up to 304.4 MPa after T6 heat treated, which is close to that of 6061 forging aluminum alloy.

Study on Microstructures and Properties of 22Mn2SiVBS Steel on Different Cooling Rate

2012 ◽  
Vol 535-537 ◽  
pp. 768-771
Author(s):  
Min Wang ◽  
Hong Xin ◽  
Shu Lan Guo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Fine Grain ◽  
Proeutectoid Ferrite ◽  
Microstructures And Mechanical Properties

Abstract:The microstructures and mechanical properties of 22Mn2SiVBS steel after austenitizing at 1280°C and then cooling in air and piled up after rolled were studied in this paper .the results show that when 22Mn2SiVBS steel cooling in air it can obtain the fine grain granular bainte and remain austenite,and piled up after rolled it can obtain granular bainte and proeutectoid ferrite. After heat treatment the strength and hardness is higher than the sample piled up after rolled, but the toughness is lower.

Microstructures and Mechanical Properties of Mg-Zn-RE-Ca Casting Alloys

2006 ◽  
Vol 510-511 ◽  
pp. 214-217 ◽  
Author(s):  
Joong Hwan Jun ◽  
Bong Koo Park ◽  
Jeong Min Kim ◽  
Ki Tae Kim ◽  
Woon Jae Jung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Eutectic Phase ◽  
Tensile Yield Strength ◽  
X Ray ◽  
Casting Alloys ◽  
Microstructures And Mechanical Properties ◽  
Strong Segregation

Influences of Ca addition on microstructures and mechanical properties at room and elevated temperatures up to 300oC were investigated for ZE41 (Mg-4%Zn-1%Zn)-(0~1.0)%Ca permanent mould casting alloys, based on the results from X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and tensile tests. The microstructure of ZE41 alloy is characterized by dendritic α-(Mg) grains surrounded by Mg7Zn3-based eutectic network phase. The average size of α grains decreases continuously with an increase in Ca content. The Ca-containing ZE41 alloys have Mg7Zn3-(RE)-(Ca) eutectic phase, in which Ca is distributed inhomogeneously owing to its strong segregation power. It is noteworthy that tensile yield strength (YS) for the ZE41 alloy was enhanced with increasing Ca content at all temperatures up to 300oC, which demonstrates that Ca can play a beneficial role in improving its tensile strength at room and elevated temperatures. The ZE41 alloy with 0.5%Ca showed the highest ultimate tensile strength (UTS) at room temperature, but in the range of 175 to 300oC, the higher the Ca content, the greater the UTS. The improved tensile strength of the Ca-containing ZE41 alloy would be caused by the refined α grains and higher thermal stability of the Mg7Zn3-(RE)-(Ca) eutectic phase.

scholarly journals On the Grain Microstructure–Mechanical Properties Relationships in Aluminium Alloy Parts Fabricated by Laser Powder Bed Fusion

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1175
Author(s):  
Pavel A. Somov ◽  
Eugene S. Statnik ◽  
Yuliya V. Malakhova ◽  
Kirill V. Nyaza ◽  
Alexey I. Salimon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Aluminium Alloy ◽  
Young’S Modulus ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Grain Morphology ◽  
Tensile Tests ◽  
Grain Structure ◽  
Surface Finishing

Recent years witnessed progressive broadening of the practical use of 3D-printed aluminium alloy parts, in particular for specific aerospace applications where weight saving is of great importance. Selective laser melting (SLM) is an intrinsically multi-parametric fabrication technology that offers multiple means of controlling mechanical properties (elastic moduli, yield strength, and ductility) through the control over grains size, shape, and orientation. Targeted control over mechanical properties is achieved through the tuning of 3D-printing parameters and may even obviate the need of heat treatment or mechanical post-processing. Systematic studies of grain structure for different printing orientations with the help of EBSD techniques in combination with mechanical testing at different dimensional levels are the necessary first steps to implement this agenda. Samples of 3D-printable Al-Mg-Si RS-333 alloy were fabricated in three orientations with respect to the principal build direction and the fast laser beam scanning direction. Sample structure and proper-ties were investigated using a number of techniques, including EBSD, in situ SEM tensile testing, roughness measurements, and nanoindentation. The as-printed samples were found to display strong variation in Young’s modulus values from nanoindentation (from 43 to 66 GPa) and tensile tests (from 54 to 75 GPa), yield stress and ultimate tensile strength (100–195 and 130–220 MPa) in different printing orientations, and almost constant hardness of about 0.8 GPa. A further preliminary study was conducted to assess the effect of surface finishing on the mechanical performance. Surface polishing was seen to reduce Young’s modulus and yield strength but improves ductility, whereas the influence of sandblasting was found to be more controversial. The experimental results are discussed in connection with the grain morphology and orientation.

Effect of TiO2 Addition on the Microstructures and Mechanical Properties of γ-TiAl Intermetallics

2011 ◽  
Vol 211-212 ◽  
pp. 205-208 ◽  
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Jiang Jing Wang
Keyword(s):  
Mechanical Properties ◽  
Strengthening Mechanism ◽  
Reaction Synthesis ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tial Intermetallics ◽  
Universal Properties ◽  
Microstructures And Mechanical Properties ◽  
Particulate Reinforced

Al2O3 Particulate reinforced TiAl based composites have been fabricated by hot press-assisted reaction synthesis (HPRS) method using Ti, Al and TiO2 as starting materials. Effect of the TiO2 addition on the microstructures and mechanical properties of the TiAl/Al2O3 composites were detailedly investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and universal properties tests. The results show that the TiO2 addition has evident effect on phase composition and microstructure of the TiAl intermetallics, as a result, the mechanical properties of TiAl composites are improved. When the TiO2 content is 10.58 wt %, the flexural strength and fracture toughness reach the maximum values of 537.34 MPa and 9.38 MPa·m1/2, which are increased by 70% and 23%, respectively. The strengthening mechanism is also discussed.

scholarly journals Effects of Cooling Rate during Quenching and Tempering Conditions on Microstructures and Mechanical Properties of Carbon Steel Flange

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4186 ◽  
Author(s):  
Haeju Jo ◽  
Moonseok Kang ◽  
Geon-Woo Park ◽  
Byung-Jun Kim ◽  
Chang Yong Choi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Cooling Rate ◽  
Charpy Impact ◽  
Hardness Test ◽  
Finite Element Method Simulation ◽  
Secondary Phases ◽  
Practical Applications ◽  
Low Temperature Toughness ◽  
Microstructures And Mechanical Properties

This study investigated the mechanical properties of steel in flanges, with the goal of obtaining high strength and high toughness. Quenching was applied alone or in combination with tempering at one of nine combinations of three temperatures TTEM and durations tTEM. Cooling rates at various flange locations during quenching were first estimated using finite element method simulation, and the three locations were selected for mechanical testing in terms of cooling rate. Microstructures of specimens were observed at each condition. Tensile test and hardness test were performed at room temperature, and a Charpy impact test was performed at −46 °C. All specimens had a multiphase microstructure composed of matrix and secondary phases, which decomposed under the various tempering conditions. Decrease in cooling rate (CR) during quenching caused reduction in hardness and strength but did not affect low-temperature toughness significantly. After tempering, hardness and strength were reduced and low-temperature toughness was increased. Microstructures and mechanical properties under the various tempering conditions and CRs during quenching were discussed. This work was based on the properties directly obtained from flanges under industrial processes and is thus expected to be useful for practical applications.

Sign in / Sign up

Export Citation Format

Share Document