Effect of Overheating on the Mechanical and Plastic Properties of A390.0 Cast Alloy

2013 ◽  
Vol 211 ◽  
pp. 9-14
Author(s):  
Jaroslaw Piątkowski
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Alloy Composition ◽  
Cast Alloy ◽  
Primary Silicon ◽  
Grain Structure ◽  
Automotive Applications ◽  
Plastic Properties ◽  
Silicon Crystals ◽  
Fine Grain

The paper presents the results of studies on the effect of the A390.0 (AlSi17Cu5) alloy overheating to a temperature of 920°C and modification with phosphorus (CuP10) on the resulting mechanical (HB, Rm, R0.2) and plastic (A5and Z) properties. It has been shown that, so-called, "time-thermal treatment" (TTT) of an alloy in the liquid state, consisting in overheating the metal to about 250÷300°C above Tliq, holding at this temperature and rapid cooling, refines the structure and improves the mechanical properties. It has also been found that strong overheating of alloy above Tliq"enhances" the process of modification, resulting in the formation of fine-grain structure. The primary silicon crystals uniformly distributed in the eutectic and characteristics of the α (Al) solution supersaturated with alloying elements present in the starting alloy composition (Cu, Fe) provide not only an increase of strength at ambient temperature but also at elevated temperature (250°C), which is of particular importance for the automotive applications, especially as regards cast pistons operating in IC.

scholarly journals The Mechanical Properties of AlSi17Cu5 Cast Alloy after Overheating and Modification of CuP Master Alloy

2013 ◽  
Vol 13 (3) ◽  
pp. 68-71
Author(s):  
J. Piątkowski ◽  
M. Jabłońska
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Master Alloy ◽  
Liquid State ◽  
Alloy Composition ◽  
Cast Alloy ◽  
Primary Silicon ◽  
Grain Structure ◽  
Silicon Crystals ◽  
Fine Grain

Abstract The paper presents the results of studies on the effect of the AlSi17Cu5 alloy overheating to atemperature of 920°C and modification with phosphorus (CuP10) on the resultingmechanical (HB, Rm, R0.2) and plastic (A5 and Z) properties. It has been shown that, so-called, "timethermal treatment" (TTT) of an alloy in the liquid state, consisting inoverheating the metal to about 250°C above Tliq,holding at this temperature by 30 minutes improvesthe mechanical properties. It has also been found that overheating of alloy above Tliq.enhances the process of modification, resulting in the formation of fine-grain structure. The primary silicon crystals uniformly distributed in the eutectic and characteristics ofthe α(Al) solution supersaturated with alloying elements present in the starting alloy composition (Cu, Fe) provide not only an increase of strength at ambient temperature but also at elevated temperature (250°C).

Evolution of Microstructure and Mechanical Properties of the Thixo-Diecast 319s Alloy during Heat Treatment

2013 ◽  
Vol 765 ◽  
pp. 511-515 ◽  
Author(s):  
Da Quan Li ◽  
Xiao Kang Liang ◽  
Fu Bao Yang ◽  
You Feng He ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Alloy ◽  
Grain Structure ◽  
Precipitate Size ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Optimum Heat ◽  
Evolution Of Microstructure

The evolution of microstructure and mechanical properties during solution and ageing heat treatment process was studied in terms of a thixo-diecast impeller of 319s aluminium alloy. The cast alloy exhibited a microstructure consisting of primary uniformly distributed in α-Al globules and the eutectics. A series of heat treatment studies were performed to determine optimum heat treatment parameters, in order to achieve fine grain structure, fine silicon particles and optimal precipitate size and distribution. Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study the evolution of microstructure and mechanical properties. The results demonstrate that, the full T6 heat treatments are successfully applied to thixo-diecast 319s impellers. A two-step solution heat treatment is employed to prevent porosity due to overheating. The tensile properties of thixo-diecast 319s impellers were substantially enhanced after T6 heat treatment. The plate-shaped θ′ precipitates and lath-shaped Q′ precipitates are the most effective for precipitation strengthening.

Severe plastic deformation of Al-1%Cu Alloy processed by a Simple Cyclic Extrusion Compression technique

2018 ◽  
Vol 1 (1) ◽  
pp. 77-90
Author(s):  
Walaa Abdelaziem ◽  
Atef Hamada ◽  
Mohsen A. Hassan
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Deformation Behavior ◽  
Cast Alloy ◽  
Surface Hardness ◽  
Grain Structure ◽  
Compression Technique ◽  
Cu Alloy ◽  
Cyclic Extrusion Compression

Severe plastic deformation is an effective method for improving the mechanical properties of metallic alloys through promoting the grain structure. In the present work, simple cyclic extrusion compression technique (SCEC) has been developed for producing a fine structure of cast Al-1 wt. % Cu alloy and consequently enhancing the mechanical properties of the studied alloy. It was found that the grain structure was significantly reduced from 1500 µm to 100 µm after two passes of cyclic extrusion. The ultimate tensile strength and elongation to failure of the as-cast alloy were 110 MPa and 12 %, respectively. However, the corresponding mechanical properties of the two pass CEC deformed alloy are 275 MPa and 35%, respectively. These findings ensure that a significant improvement in the grain structure has been achieved. Also, cyclic extrusion deformation increased the surface hardness of the alloy by 49 % after two passes. FE-simulation model was adopted to simulate the deformation behavior of the material during the cyclic extrusion process using DEFORMTM-3D Ver11.0. The FE-results revealed that SCEC technique was able to impose severe plastic strains with the number of passes. The model was able to predict the damage, punch load, back pressure, and deformation behavior.

Characterization of mechanical properties of aluminum cast alloy at elevated temperature

2018 ◽  
Vol 39 (7) ◽  
pp. 967-980 ◽  
Author(s):  
Shuiqiang Zhang ◽  
Yichi Zhang ◽  
Ming Chen ◽  
Yanjun Wang ◽  
Quan Cui ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Cast Alloy

Microstructures and Properties of Biological Mg-Zn-Y-Nd Alloy by Friction Stir Processing

2013 ◽  
Vol 745-746 ◽  
pp. 33-38 ◽  
Author(s):  
Shi Jie Zhu ◽  
Li Guo Wang ◽  
Jin Jin ◽  
Jing Wang ◽  
Yu Feng Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Processing ◽  
Cast Alloy ◽  
Corrosion Current ◽  
Stir Zone ◽  
Grain Structure ◽  
Second Phase ◽  
Uniform Corrosion ◽  
Corrosion Properties ◽  
Friction Stir

In order to improve the mechanical properties and processing performance of the Mg alloys, and to prevent magnesium alloy from non-uniform corrosion and too fast degradation in the degradation process, the biological medical Mg-Zn-Y-Nd alloy was modified by the friction stir processing (FSP) technique in this paper. The microstructural evolution and phase constitute of the stir zone of Mg-Zn-Y-Nd alloy were investigated, the microhardness and the corrosion properties of the alloy after FSP process was studied. The results showed that the FSP parameters had significant influence on the stir zone and thermo-mechanically affected zone. The stir zone experienced severe plastic deformation and complete dynamic recrystallization after FSP. The stir zone consists of fine equiaxed recystallized grains, and thermo-mechanically affected zone (TMAZ) has deformed grain structure. The second phase distributed along grain boundaries in as-cast state was broken during the FSP and transformed into fine, uniform and dispersed particles in the grains. After FSP, the size of grains was reduced from 50μm (as-cast alloy) to 1-2μm. However, the second phase constitution didnt change. The alloy obtained good comprehensive mechanical properties after FSP. The microhardness of alloy after FSP increased from 39HV (as-cast alloy) to 64HV(FSPed alloy). The results of electrochemical tests in simulated body fluid showed that the corrosion potential of FSP alloy increased and corrosion current density decreased, which confirmed the uniform corrosion of FSPed alloy.

scholarly journals Generation of increased mechanical properties of Cantor high­entropy alloy

2021 ◽  
Vol 64 (8) ◽  
pp. 599-605
Author(s):  
V. E. Gromov ◽  
Yu. A. Rubannikova ◽  
S. V. Konovalov ◽  
K. A. Osintsev ◽  
S. V. Vorob’ev
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Bimodal Distribution ◽  
Additive Technology ◽  
Plastic Properties ◽  
Torsional Strain ◽  
Dislocation Glide ◽  
Electron Beam Processing ◽  
Strength And Plasticity ◽  
High Level

The article considers a brief review of the last years of Russian and foreign research on the possibilities of improving mechanical properties of the Cantor quinary high­entropy alloy (HEA) with different phase composition in wide temperature range. The alloy, one of the frst created equimolar HEAs with FCC structure, needs mechanical properties improvement in accordance with possible felds of application in spite of its high impact toughness and increased creep resistance. It has been noted that bimodal distribution of the grains by sizes under severe plastic torsional strain at high pressure of 7.8 GPa of cast alloy and subsequent short­time annealing at 873 and 973 K can change strength and plastic properties. Nanodimensional scale of the grains surrounded by amorphous envelope has been obtained for HEA produced by the method of magnetron sputtering and subsequent annealing at 573 K. In such a two­phase alloy nanohardness amounted to 9.44 GPa and elasticity modulus – to 183 GPa. Using plasticity effect induced by phase transformation in (CrMnFeCoNi)50Fe50 alloy obtained by the method of laser additive technology the ultimate strength of 415 – 470 MPa has been reached at high level of plasticity up to 77 %. It has been ensured by FCC → BCC diffusionless transformation. It is shown that difference in mechanisms of plastic strain of cast alloy at 77 K and 293 K (dislocation glide and twinning) determines a combination of increased “strength­plasticity” properties. Samples for generation of twins prestrained at 77 K exhibit increased strength and plasticity under subsequent loading at 293 K in comparison with the unstrained ones. For HEA obtained by laser additive technology this way of increasing properties is also true. The way of improving mechanical properties at the expense of electron beam processing is noted. The attention is paid to the necessity of taking into account the role of entropy, crystal lattice distortions, short­range order, weak diffusion and “cocktail” effect in the analysis of mechanical properties.

Investigation of Microstructure and Mechanical Properties of Carbon Steel Wire after Continuous Method of Deformation Nanostructuring

2013 ◽  
Vol 436 ◽  
pp. 114-120 ◽  
Author(s):  
Marina Polyakova ◽  
Alexandr Gulin ◽  
Dmitriy Constantinov
Keyword(s):  
Carbon Steel ◽  
Steel Wire ◽  
Strength Properties ◽  
Russian Federation Patent ◽  
Carbon Steels ◽  
Continuous Method ◽  
Grain Structure ◽  
Plastic Properties ◽  
Fine Grain ◽  
Efficiency Estimation

The continuous method of wire deformation nanostructuring is developed on the basis of simultaneous applying of tension deformation by drawing, bending deformation when going through the system of rolls and torsional deformation on a continuously moving wire. The patent for an invention of the Russian Federation patent office is got. The efficiency estimation of the developed continuous method of deformation nanostructuring was carried out using wire made of medium and high-carbon steels containing 0.2 and 0.75 % C. The wire processed by this method has a uniform ultra-fine grain structure across the cross-section without internal discontinuities that indicates the possibility of combining different deformation schemes for achieving this type of structure in wire. Not only increasing strength properties of carbon steel wire is achieved after this method but increasing plastic properties occurs at the same time.

Microstructure and Mechanical Properties of Extruded Mg-Zn-Nd-Y-Zr-Ca Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 385-388
Author(s):  
Qiang Li ◽  
Qu Dong Wang ◽  
Xiao Qing Zeng ◽  
Wen Jiang Ding ◽  
Quanbo Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Cast Alloy ◽  
Casting Process ◽  
Elevated Temperature Strength ◽  
The Matrix ◽  
Zr Alloys

Nd, Y and Ca containing Mg-Zn-Zr alloys are produced by electromagnetic direct-chilling casting process, and extruded at a temperature of 643K with two extrusion ratios of 38:1 and 22:1, respectively. The grain size is markedly reduced from 80µm in as-cast alloy to 2~5µm in as-extruded alloy due to dynamic recrystallization, and lamellar eutectics at grain boundaries in as-cast alloy are broken up and fine precipitates in the matrix come forth during hot extrusions. Mechanical properties of the alloys are measured by tensile test from room temperature to 523K. Nd, Y and Ca are favorable to the strength of the hot-extruded alloy, especially the elevated-temperature strength, which is above 200MPa in ultimate tensile strength at 523K.

Novel Grain Refiner for Hypo- and Hyper-Eutectic Al-Si Alloys

2011 ◽  
Vol 690 ◽  
pp. 49-52 ◽  
Author(s):  
Magdalena Nowak ◽  
Nadendla Hari Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Al Alloys ◽  
Grain Structure ◽  
Grain Refiner ◽  
Silicon Alloys ◽  
Fine Grain ◽  
Cooling Conditions ◽  
Wide Range ◽  
Master Alloys

A novel effective grain refiner for hypo and hyper-eutectic Aluminium-Silicon alloys has been developed. The composition of the grain refiner has been optimized to produce a fine grain structure and finer eutectic. Effectiveness of grain size under various cooling conditions has also been investigated to simulate various practical casting conditions. For comparative purposes, a wide range of Al alloys have been produced with the addition of commercially available Al-5Ti-B master alloys. The results show that the addition of novel grain refiner reduces the grain size significantly. As a result of fine grains, the porosity in the solidified alloys is remarkably lower. A notable improvement in mechanical properties has also been observed.

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