Comparing the SEED Semi-Solid Process to Low Pressure Permanent Mould in the Production of 4mm Thick Aluminum A356 Covers

2013 ◽  
Vol 765 ◽  
pp. 112-116
Author(s):  
Franco Chiesa ◽  
David Levasseur ◽  
Jocelyn Baril

In order to compare the semi-solid SEED casting process to the Low Pressure Permanent Mould process (LPPM), the same part has been produced in aluminium A356 (AlSi7Mg04) using the two methods. The processes were first compared from an operational standpoint: pouring temperature, filling sequence, production rate and mould maintenance. In addition, the metallurgical quality of the castings was evaluated by measuring the tensile properties at 6 locations in the part; the metallographic structures were also compared. Filling and solidification modeling allowed the prediction of the filling sequence and local solidification times everywhere in the casting. The SEED process was generally found to deliver a finer structure, a near net shape casting and a much higher productivity. LPPM parts were more uniform in structural and mechanical properties as verified at 6 locations in the castings.

2019 ◽  
Vol 269 ◽  
pp. 07001 ◽  
Author(s):  
Donanta Dhaneswara ◽  
Jaka Fajar Fatriansyah ◽  
Raffi Ramadhan ◽  
Ahmad Ashari

The effect of NaF and NaNO3 based degasser on mechanical properties of Al-Si 12% casting has been investigated. The quality of Al-Si casting, especially in mechanical properties, is important in some applications. However, the existence of gas porosity, which is formed due to the high solubility of H2 at melt temperature in casting process, reduces mechanical propertis of Al-Si 12% casting product. In this research, we used NaF and NaNO3 as degasser as an addition in casting process. The experiments were conducted at pouring temperature of 660°C, 680°C, 700°C and 720°C. The mechanical properties (which are determined by tensile test, hardness test and impact test) with and without degasser were measured and compared. We found that in all pouring temperature, the addition of degasser will improve all of mecahnical properties measured. In addition we found that the increase of tensile strength was optimum at pouring temperature of 720°C at 25,5 % of increase, hardness was optimum at pouring temperature of 720°C at 33,3 % of increase and impact strength was optimum at pouring temperature of 720°C at 25 % of increase. The improvement of mechanical properties is due to the role of NaF and NaNO3 by binding H2 gases which is formed in melting process. This H2 binding was shown in microstructure observation which shows that the porosity of casting product visually decreased.


2012 ◽  
Vol 538-541 ◽  
pp. 1134-1137
Author(s):  
Da Chun Yang

For the steel castings which is thin wall, uniform thickness, complex structure, and no special mechanical properties, it is feasible that the foundry technology was designed according to the last solidifying feeding mechanism. Adopting this process for the thin wall steel castings, the pouring temperature must be controlled and the gating system be designed rationally. Using self-feeding shrinkage in solidification, and the casting was poured and congealing at the same time. The shrinkage of finally congealing part was fed by small riser or gating system (no riser). Using this foundry technology, the casting process yield and surface quality of casting may be improved, the production cost is reduced, and the requirements of mechanical properties can be met.


2016 ◽  
Vol 879 ◽  
pp. 530-535
Author(s):  
Xiao Gang Fang ◽  
Shu Sen Wu ◽  
Shu Lin Lü

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.


2015 ◽  
Vol 651-653 ◽  
pp. 1569-1574 ◽  
Author(s):  
Asnul Hadi Ahmad ◽  
Sumsun Naher ◽  
Dermot Brabazon

Abstracts: This paper presents an overview of measured mechanical properties of thixoformed aluminium 7075 feedstock produced by the direct thermal method (DTM). The DTM feedstock billets were processed with a pouring temperature of 685 °C and holding periods of 20 s, 40 s and 60 s before being quenched and subsequently thixoformed. A conventionally cast feedstock billet was produced with a pouring temperature of 685 °C and was allowed to solidify without quenching. The feedstock billets were later formed by an injection test unit in the semi-solid state. Tensile testing was then conducted on the thixoformed feedstock billets. Tensile properties for 7075 DTM thixoformed feedstock billets were found significantly influenced by the thixoformed component density. Samples with longer holding times were found to have higher density and higher tensile strength.


2015 ◽  
Vol 825-826 ◽  
pp. 167-175
Author(s):  
Andreas Storz ◽  
Thomas Schubert ◽  
Thomas Weissgärber ◽  
Christoph Seyboldt ◽  
Kim Rouven Riedmüller

The paper describes a cost effective and innovative combination of direct pressure sintering and subsequent thixoforming to produce MMC-components in (near-) net shape quality and, thus, to make these interesting materials attractive to mass production.First results of some combinations of aluminium matrix alloys with different ceramic reinforcements, consolidated by fast pressure sintering show the efficiency of this technology.The further processing of the consolidated billets has been performed by thixoforging. It can be shown, that the homogeneous microstructure from the direct pressure sintering stage with uniformly distributed ceramic reinforcements can be maintained over the semi-solid state and a full densification can be achieved. Form filling was complete and surface quality was comparable to forgings from conventional alloys.This new process flow shows advantages regarding the material yield in each of the processing steps. The (near-) net shape quality of thixoforged components allows a reduced effort for machining, which is of special importance for composite materials with a high content of wear resistant hard phases like SiC-particles.


2014 ◽  
Vol 217-218 ◽  
pp. 332-339 ◽  
Author(s):  
Xiao Kang Liang ◽  
Da Quan Li ◽  
Pascal Côté ◽  
Stephen P. Midson ◽  
Qiang Zhu

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.


2013 ◽  
Vol 411-414 ◽  
pp. 3064-3067 ◽  
Author(s):  
Han Wu Liu ◽  
Zhi Ping Zhang ◽  
Yan Fang Luo ◽  
Li Lu

In order to reduce the wear of parts caused by long-term friction, and to reduce the frequency of parts replacement, ZA alloy with low hardness and good wear resistance is chosen to replace the traditional copper alloy as the material to manufacture automotive bushing, and the semi-solid die casting is used. On this basis, the software AnyCasting is used to simulate and analyze the filling and solidification process, the filling sequence, the variation of temperature field, and the part region where defects are prone to occur in the semi-solid process. The simulation results show that under the parameters set in the simulation process, when casting filling rate reached 90%, the metal started to solidify; since the gate place is easy for heat dissipation, when the temperature of the alloy liquid reached its liquidus temperature 595°C, the phenomenon of solid-liquid phase separation appeared at the gate; the defects such as gas trapping, residual stress and deformation would appear both in the place of first filling and the parting surface; when the preheat temperature of the mold was 150°C-200°C,the alloy liquid possesses liquidity. The simulation results offer certain theoretical instruction to optimize the semi-solid casting process of ZA Alloy automotive bushing manufacturing, as well as reducing or avoiding a variety of quality defects arose in the actual casting process.


2011 ◽  
Vol 189-193 ◽  
pp. 2096-2102 ◽  
Author(s):  
Xin Zhao ◽  
Yan Wei Sui ◽  
Ai Hui Liu ◽  
Fei Fei Wang ◽  
Zhi Sun ◽  
...  

Using the method of numerical simulation and the AnyCasting software, the simulation for SDAS of Al-Mg alloy wheels for low pressure casting is studied. The simulation model is established and the effects of preheating temperature, melt pouring temperature and cooling water pipes on SDAS in the low pressure casting process was founded. The results show that, SDAS presents linear variation with the increase of preheating temperature and pouring temperature; opened cooling pipes make SDAS smaller. The practice of simulating casting is verified by experiments, and test results and simulation results were consistent.


2011 ◽  
Vol 264-265 ◽  
pp. 272-277 ◽  
Author(s):  
Nurşen Saklakoğlu ◽  
S. Gencalp ◽  
Şefika Kasman ◽  
İ.E. Saklakoğlu

Thixoforming and related semi-solid processing (SSP) methods require thixotropic materials. One of the many SSP techniques is the cooling slope (CS) casting process, which is simple and has minimal equipment requirements, and which is able to produce feedstock materials for semisolid processing. When the feedstock is reheated to the semisolid temperature range, non-dendritic, spheroidal solid particles in a liquid matrix suitable for thixoforming are obtained. In this study, equipment for the CS technique was first established, and then the effects of the pouring temperature and inclined slope angle on the microstructures of A380 aluminum alloy (ISOAlSi8Cu3Fe) were studied. Optimum parameters for thixoforming experiments were selected, and it was found that the microstructure produced by the inclined plate depended on its angle and the pouring temperature.


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