Research on the Preparation and Rheo-Casting of A356 Al Alloy by LSPWES Process

2012 ◽  
Vol 457-458 ◽  
pp. 69-73
Author(s):  
Man Huan Li ◽  
Guo Xing Tang ◽  
Wei Min Mao ◽  
Yong Feng Liu
Keyword(s):  
Proper Time ◽  
Great Influence ◽  
Injection Pressure ◽  
Experimental Results ◽  
Temperature Fields ◽  
Homogeneous Distribution ◽  
Semisolid Slurry ◽  
Al Alloy ◽  
Injection Speed ◽  
Filling Ability

The semisolid slurry of A356 Al alloy was prepared by low superheat pouring and weak traveling-wave electromagnetic stirring (LSPWES), and then the slurry was further soaked for proper time and finally rheo-cast into a rheo-casting sample in this paper. The experimental results show that if the melt of A356 Al alloy is poured at 630-650°C and meanwhile stirred by weak electromagnetic field for a short time, the most primary α-Al grains solidified in the slurry are spherical and only a few are rosette-like. The shape of primary α-Al becomes more spheroidal and more homogeneous distribution in the microstructure by the process of the uniform temperature fields. The experimental results also show that the slurry temperature, injection pressure and speed have a great influence on filling ability. The higher the slurry temperature, injection pressure and speed, the higher the slurry filling ability, the more easily the die cavity is filled. With the given rheo-casting sample, if only the slurry temperature should be equal to or more than 585°C, or the injection pressure is equal to or more than 20 MPa, or the injection speed should be equal to or more than 0.24m/s, the rheo-casting sample die cavity can be filled completely. The microstructure of the castings indicates that the shape, size and numbers of the primary α-Al grains in different parts of the castings are highly consistent. After being held at 535 °C for 5 h and then aged at 160 °C for 16 h, the tensile strength, elongation rate and hardness of the rheo-casting samples with the above process are respectively 321.5 MPa, 8.03% and 105.9HB.

Research on the Composite Slurry Preparation and Rheocasting of Aluminum Alloy

2006 ◽  
Vol 116-117 ◽  
pp. 410-416 ◽  
Author(s):  
Wei Min Mao ◽  
Yue Long Bai ◽  
Song Fu Gao ◽  
Guo Xing Tang
Keyword(s):  
Electromagnetic Field ◽  
Low Power ◽  
Proper Time ◽  
Great Influence ◽  
Injection Pressure ◽  
Experimental Results ◽  
Semisolid Slurry ◽  
Injection Speed ◽  
Filling Ability ◽  
Short Time

The study on new rheoforming technologies of semisolid alloys has recently been one main subject interesting many professors, experts and industrials, and so many new methods about preparing semisolid alloy slurry and rheoforming process have been put forward. The semisolid slurry of AlSi7Mg alloy was prepared by being poured at a low superheat and stirred by an electromagnetic field at a low power for a short time, and then the slurry was further soaked for proper time and finally rheoformed into a key-shaped die cavity in this paper. The influence of slurry temperature, injection specific pressure and injection speed on the rheoforming process was also studied. The experimental results show that if AlSi7Mg alloy melt is poured at 630°C or 650°C and meanwhile stirred by an electromagnetic field at a low power for a short time, the most primary α-Al grains solidified in the slurry are spherical and only a few are rosette-like. If the slurry after made is then soaked in the liquidus-solidus range for some time, the ripening of primary α-Al grains is developed further and they become more spherical and larger. The experimental results also show that the slurry temperature, injection pressure and speed have a great influence on filling ability. The higher the slurry temperature, injection pressure and speed, the higher the slurry filling ability, and the shorter the core distance from the ingate, the more easily the die cavity is filled. With the given key-shaped casting, if only the slurry temperature should be equal to or more than 585,, or the injection pressure is equal to or more than 20 MPa, or the injection speed should be equal to or more than 1.73m/s, the key-shaped die cavity can be filled completely. The microstructural distribution in the casting is very homogeneous and it shows that the slurry prepared by the new method is very suitable for rheoforming and helpful to obtaining high quality castings.

Microstructure and Mechanical Properties of Fe-Containing Al-Alloys Processed by a Rheo-Diecasting Process

2006 ◽  
Vol 519-521 ◽  
pp. 1251-1256
Author(s):  
X. Fang ◽  
G. Shao ◽  
Z. Fan
Keyword(s):  
Mechanical Properties ◽  
High Efficiency ◽  
Low Cost ◽  
Al Alloys ◽  
Experimental Results ◽  
Semisolid Slurry ◽  
Al Alloy ◽  
Twin Screw ◽  
Size And Morphology ◽  
Plate Morphology

Al-Fe compounds are usually present in the as-cast microstructure of Al-alloys as large needles or plates. As such, they have a detrimental effect on the mechanical properties of Al-alloys containing Fe, either as an impurity element or as an alloying addition. However, Fe-containing Al-alloys also offer attractive physical properties, such as improved stiffness, wear resistance and thermal resistance. If the needle and plate morphology of the Al-Fe compounds can be modified to a more compact morphology, with refined particle size and uniform distribution, the mechanical properties of Al-Fe based Al-alloys can be substantially improved, and therefore, they will find wider applications in many engineering sectors. A new semisolid metal processing technology, rheodiecasting (RDC), has been developed for production of Al-alloy components with high integrity. The RDC process innovatively combines the dispersive mixing power of the twin-screw mechanism, for the creation of high quality semisolid slurry, with the high efficiency, low cost nature of the high-pressure diecasting (HPDC) process for component shaping. In this paper, we present our experimental results on the effects of intensive melt shearing on the size and morphology of Al-Fe compounds in A380 alloys, with different levels of Fe additions. The experimental results have shown that intensive melt shearing during solidification can effectively change the particle shape from the usual needles and plates, to an equiaxed morphology. Samples which have undergone with melt shearing, exhibit much improved strength and ductility compared to those with the same level of Fe addition, but without exposure to melt shearing.

Flow and Temperature Fields Measurement Inside Rod Bundle by the Combined Use of PIV and LIF Technique

2018 ◽  
Author(s):  
Xing Li ◽  
Sichao Tan ◽  
Zhengpeng Mi ◽  
Peiyao Qi ◽  
Yunlong Huang
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Great Influence ◽  
Reactor Core ◽  
Transfer Characteristic ◽  
Index Of Refraction ◽  
Temperature Fields ◽  
Spacer Grid ◽  
Rod Bundle ◽  
Combined Use

Thermal hydraulic research of reactor core is important in nuclear energy applications, the flow and heat transfer characteristics of coolant in reactor fuel assembly has a great influence on the performance and safety of nuclear power plants. Particle image velocimetry (PIV) and Laser induced fluorescence (LIF) are the instantaneous, non-intrusive, whole-field fluid mechanics measuring method. In this study, the simultaneous measurement of flow field and temperature field for a rod bundle was conducted using PIV and LIF technique. A facility system, utilizing the matching index of refraction approach, has been designed and constructed for the measurement of velocity and temperature in the rod bundle. In order for further study on complex heat and mass transfer characteristic of rod bundle, the single-phase experiments on the heating conditions are performed. One of unique characteristics of the velocity and temperature distribution downstream the spacer grid was obtained. The experimental results show that the combined use of PIV and LIF technique is applied to the measurement of multi-physical field in a rod bundle is feasible, the measuring characteristics of non-intrusive ensured accuracy of whole field data. The whole field experimental data obtained in rod bundle benefits the design of spacer grid geometry.

scholarly journals Influence of Nanoparticles Reinforcements on Aluminium 6061 Alloys Fabricated via Novel Ultrasonic Aided Rheo-Squeeze Casting Method

2021 ◽  
Author(s):  
T. Arunkumar ◽  
Velmurugan Pavanan ◽  
Vijay Anand Murugesan ◽  
V. Mohanavel ◽  
Karthikeyan Ramachandran
Keyword(s):  
Squeeze Casting ◽  
Mechanical Performance ◽  
Thermal Studies ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Mechanical And Thermal Properties ◽  
The Novel ◽  
Morphological Studies ◽  
Agglomeration Of Nanoparticles ◽  
Disperse Nanoparticles

Abstract This study emphasis on a novel fabrication technique to fabricate hybrid cermets using Al 6061 alloy with nano sized SiC, Al2O3 and TiO2 as reinforcements. During the fabrication process, the melted pool was ultrasonicated to disperse nanoparticles at 20 kHz for 5 min and pressure of 50 MPa was applied to eliminate voids. The influence of nanoparticles on physical, thermal and mechanical properties were evaluated by tensile, wear and thermal studies. Cermets with Al2O3 reinforcements showed higher mechanical performance compared to Al alloy. This enhancement could be related to the uniform distribution of Al2O3 with refinement in grain size of Al alloy which was observed via surface analysis. The morphological studies provided justifiable evidence of homogeneous distribution, nominal cluster along with agglomeration and cavities shrinking on the cermets. The agglomeration of nanoparticles along with SiC protected the cermet in corrosion and abrasive wear by ~ 97% and ~ 71%. The study evidenced the novel fabrication method using ultrasonic rheo-squeeze casting led to improvement in mechanical and thermal properties of the hybrid cermets. Graphical abstract

Significance of gate geometry and injection speed on the flow behaviors of molten Al alloy during die filling

2005 ◽  
Vol 11 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Jae-Chul Lee ◽  
Hyun-Kwang Seok ◽  
Hong-Kee Lee
Keyword(s):  
Al Alloy ◽  
Injection Speed ◽  
Die Filling

Semisolid Die-Casting Process of Mg-20Al-0.8Zn Magnesium Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 539-543
Author(s):  
Feng Yun Yan ◽  
Xiao Feng Huang ◽  
Bo Li ◽  
Ying Ma
Keyword(s):  
Tensile Strength ◽  
Die Casting ◽  
Injection Pressure ◽  
Casting Process ◽  
Elongation Rate ◽  
Isothermal Heat Treatment ◽  
Technological Parameters ◽  
Injection Speed ◽  
Die Casting Process ◽  
Spherical Grains

Based on microstructure evolution of Mg-20Al-0.8Zn magnesium alloys realized by semisolid isothermal heat-treatment (SSIT), we obtained the non-dendrite or spherical grains microstructure under the suitable technological parameters that isothermal temperature is 495 °C and holding time is 120 min. With the help of special experimental equipment, the semisolid die-casting process has been studied and the specimens have been analyzed. The effects of different parameters as injection speed and pressure on tensile strength, elongation rate, hardness, etc have been investigated. The results indicate that tensile strength was improved along with increasing injection speed and pressure. However, excessive speed will involve gas, which formed defects and reduced the mechanical properties. When the injection pressure is 40MPa and injection speed is 4m/s, the tensile strength and elongation rate can reach maximal 220MPa and 5.63% respectively. Its fracture mechanism was intercrystalline cracking.

scholarly journals THE INFLUENCE OF THE METHOD OF LAYING PIPELINES ON THE ENERGY EFFICIENCY OF THE HEATING NETWORK

2019 ◽  
Vol 10 (2) ◽  
pp. 59-66
Author(s):  
E. A Biryuzova ◽  
A. S Glukhanov
Keyword(s):  
Energy Efficiency ◽  
Heat Loss ◽  
Thermal Insulation ◽  
Thermal Energy ◽  
Great Influence ◽  
Temperature Fields ◽  
Insulation Material ◽  
Design Work ◽  
Heat Networks ◽  
Insulation Thickness

Through pipelines of heat networks, due to their large length, a large amount of thermal energy is lost. Identification of technical solutions related to improving the energy efficiency of heating networks is an urgent task at present. The article is devoted to the consideration of options for laying pipelines of heat networks during design work. In the conducted studies, two main methods of underground laying of pipelines of heat networks with the choice of the most energy-efficient, with minimal losses of thermal energy are considered. Channel and channelless laying methods are investigated with the same design features and technological conditions of operation of pipelines of heat networks using the same thermal insulation material. For each option, the required thickness of the thermal insulation is determined by the normalized density of the heat flow, thermal calculations are performed to determine the heat loss and the value of the temperature fields generated around the operating pipelines of the heat networks. The obtained values of the thermal insulation thickness in the channel method of laying pipelines are 30-50 % lower than those in channelless laying. The heat loss values, according to the results of the heat calculation for the options under consideration, in the channel method of laying are reduced by 47-65 %. The temperature fields formed around the pipelines of thermal networks with channelless laying significantly exceed the natural value of the soil temperature at the depth of the pipeline. What has a great influence on the determination of the distance to adjacent pipelines and other utilities, laid underground, in the zone of the thermal network. A comparative analysis of the results obtained makes it possible to single out the choice of the method of laying the pipeline into a group of measures aimed at energy saving and increasing energy efficiency in heating systems.

Experimental Research on Rotating Skimmer

2003 ◽  
Author(s):  
Minoru Chino ◽  
Kenji Takizawa ◽  
Takashi Yabe
Keyword(s):  
Experimental Research ◽  
Rotational Speed ◽  
Rotation Speed ◽  
Experimental Results ◽  
Injection System ◽  
Benchmark Test ◽  
Injection Speed ◽  
Structure Interaction ◽  
Wide Range ◽  
Computer Codes

This paper provides the experimental results on skimmer and gives some detailed information useful for benchmark test of computer codes that are now able to simulate the fluid-structure interaction. For this purpose, we specially designed the injection system that imposes reproducible rotational speed and injection speed on the skipper. The effect of rotation is discussed by changing rotation speed in a wide range.

Effect of Processing Conditions on the Shrinkage and Warpage of Glass Fiber Reinforced PP Using Microcellular Injection Molding

2012 ◽  
Vol 501 ◽  
pp. 294-299 ◽  
Author(s):  
Zhi Bian ◽  
Peng Cheng Xie ◽  
Yu Mei Ding ◽  
Wei Min Yang
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Process Conditions ◽  
Fiber Reinforced ◽  
Injection Speed ◽  
Glass Fiber Reinforced ◽  
Microcellular Injection Molding ◽  
Molded Parts

This study was aimed at understanding how the process conditions affected the dimensional stability of glass fiber reinforced PP by microcellular injection molding. A design of experiments (DOE) was performed and plane test specimens were produced for the shrinkage and warpage analysis. Injection molding trials were performed by systematically adjusting six process parameters (i.e., Injection speed, Injection pressure, Shot temperature, SCF level, Mold temperature, and Cooling time). By analyzing the statistically significant main and two-factor interaction effects, the results showed that the supercritical fluid (SCF) level and the injection speed affected the shrinkage and warpage of microcellular injection molded parts the most.

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