Effect of Grain Refiners and/or Modifiers on the Microstructure and Mechanical Properties of Al-Si Alloy (LM6)

2019 ◽  
Vol 969 ◽  
pp. 794-799 ◽  
Author(s):  
Satya Prema ◽  
T.M. Chandrashekharaiah ◽  
P. Farida Begum
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Grain Size ◽  
Treatment Process ◽  
Test Results ◽  
Alloy Casting ◽  
Fine Grain ◽  
Melt Treatment ◽  
Microstructure And Mechanical Properties ◽  
Master Alloys

Grain refinement is one of the most important and popular melt treatment process for Al-Si alloy casting. Microstructure and mechanical properties of commercially available Aluminium Silicon alloy LM6 can be improved with the addition of grain refiners and modifiers as these provide technical and economic advantages. This paper is an effort to study the effects of addition of grain refiners and modifiers to the eutectic Al – Si alloy LM6. Commercially available Al - Si alloy LM6 (eutectic = 12% Si) is grain refined with Al-5Ti-1B and Al-3B; and modified with Al-10Sr master alloys. These were added individually and then tested for its unique mechanical properties such as ultimate tensile strength, hardness and wear; which are co-related with the machining tests such as turning, surface roughness and drilling. The test results are compared with microstructure of the samples observed through SEM.The mechanical properties of this alloy can be altered after addition of master alloys, which in turn alter the grain size. Thus the results conclude that the mechanical properties of Al-Si alloys in general are controlled by a number of principal microstructural features. A fine grain size is desirable, leading to improvement of mechanical properties.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Nanocrystalline Aluminum 5083 Alloy

2015 ◽  
Vol 782 ◽  
pp. 113-118
Author(s):  
Ying Mei Teng ◽  
Zhao Hui Zhang ◽  
Zi Zhou Yuan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Sintering Temperature ◽  
Initial Pressure ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Bulk Nanocrystalline

The bulk nanocrystalline (NC) aluminum (Al) 5083 was synthesized by spark plasma sintering (SPS) technique with low initial pressure of 1 MPa, high holding pressure of 300 MPa and holding time of 4 min at different sintering temperatures, using surface passivated nanopowders. The effect of sintering temperature on microstructure and mechanical properties of the bulk NC Al 5083 were investigated. Results indicate that the density, grain size, the hardness and the compressive strength of the bulk NC Al 5083 increase with an increase in sintering temperature. The mechanical properties of the material are greatly improved due to the fine grain size. The bulk NC Al 5083 sintered at 723 K has the highest micro-hardness of 2.37 GPa and the best compressive strength of 845 MPa.

Effects of Finish-Rolling Reduction on Microstructure and Mechanical Properties for C-Si-Mn Hot Rolled Dual-Phase Steel

2011 ◽  
Vol 339 ◽  
pp. 215-218
Author(s):  
Bin Bin Sun ◽  
Zhi Wei Jia ◽  
Hong Mei Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Dual Phase Steel ◽  
Lath Martensite ◽  
Rolling Reduction ◽  
Dual Phase ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Finish Rolling ◽  
Hot Rolled

The experiments were carried out on the φ450 hot rolling mill at the State Key laboratory of Rolling and Automatic of Northeastern University. The effect of different finish-rolling reduction on the microstructure and mechanical properties of C-Si-Mn hot rolled dual-phase steel were studied. It is found that the grain size of the ferrite would be finer with the increasing of finish-rolling reduction. Through the controlling of the finish-rolling reduction, grain size of the ferrite can be finer, so the better properties can be obtained by fine grain and sub-grain strengthened. With the low volume of lath martensite, the elongation of sample is high, the yield-strength ratio is low, and complex properties are better.

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.

Effects of Annular Electromagnetic Stirring Melt Treatment on Microstructure and Mechanical Properties of 7050 Rheo-Casting

2019 ◽  
Vol 285 ◽  
pp. 219-223 ◽  
Author(s):  
Tian Yang Guan ◽  
Zhi Feng Zhang ◽  
Min He ◽  
Yue Long Bai ◽  
Ping Wang
Keyword(s):  
Mechanical Properties ◽  
Casting Process ◽  
Hot Cracking ◽  
Electromagnetic Stirring ◽  
Solidification Structure ◽  
Alloy Casting ◽  
Melt Treatment ◽  
Microstructure And Mechanical Properties ◽  
Strength And Ductility

The microstructure and mechanical properties of 7050 alloy rheo-castings after treated by Annular Electromagnetic Stirring (A-EMS) melt treatment were investigated. The results revealed that, under A-EMS, the refinement and homogeneity of the solidification structure could be improved greatly and the slurry was suitable for the following rheo-casting; and also the hot-cracking defects in the casting process were significantly alleviated, meanwhile, the strength and ductility of the alloy casting were found to be comparable to those of conventionally forged 7000 series alloys.

Microstructure and Mechanical Performance of AZ31-1.7 Wt.% Si Alloy Processed by Cyclic Channel Die Compression

2010 ◽  
Vol 667-669 ◽  
pp. 457-461
Author(s):  
Wei Guo ◽  
Qu Dong Wang ◽  
Man Ping Liu ◽  
Tao Peng ◽  
Xin Tao Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Mechanical Performance ◽  
Chinese Script ◽  
Cast State ◽  
Microstructure And Mechanical Properties ◽  
Mean Grain Size ◽  
The Matrix ◽  
The Mean

Cyclic channel die compression (CCDC) of AZ31-1.7 wt.% Si alloy was performed up to 5 passes at 623 K in order to investigate the microstructure and mechanical properties of compressed alloys. The results show that multi-pass CCDC is very effective to refine the matrix grain and Mg2Si phases. After the alloy is processed for 5 passes, the mean grain size decreases from 300 μm of as-cast to 8 μm. Both dendritic and Chinese script type Mg2Si phases break into small polygonal pieces and distribute uniformly in the matrix. The tensile strength increases prominently from 118 MPa to 216 MPa, whereas the hardness of alloy deformed 5 passes only increase by 8.4% compared with as-cast state.

Effect of Microcast-X Fine Grain Casting on the Microstructure and Mechanical Properties of K492M Alloy at 760°C

2016 ◽  
Vol 849 ◽  
pp. 549-556
Author(s):  
Pin Pin Hu ◽  
Qi Dong Gai ◽  
Qing Li ◽  
Xin Tang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Rupture Life ◽  
Stress Rupture ◽  
Casting Alloy ◽  
Stress Rupture Life ◽  
Casting Technique ◽  
Conventional Casting ◽  
Fine Grain

The effect of Microcast-X fine grain casting on the microstructure and mechnical property K492M alloy at 760°C of was investigated. The results indicated that Microcast-X fine grain casting decreased grain size and dendrite space of γ′ phase and γ/γ′ eutectic. In addition, the element segregation decreased significantly compared to conventional casting technique. Also, the size and distribution of MC carbide were improved. By Microcast-X fine grain casting, the tensile strength increased from 934MPa of conventional casting alloy to 1089MPa and the elongation increased from 1.9% to 5.7%. In addition, the stress-rupture life increased from 28.8h of conventional casting alloy to 72.5h. And the fracture mechanism for the alloys by Microcast-X fine grain casting is trans-granular fracture toughness.

Influence of Stirring Time and Holding Time on Microstructure and Properties of the A356 Alloy Modified by Sc

2013 ◽  
Vol 750-752 ◽  
pp. 687-690 ◽  
Author(s):  
Su Zhang ◽  
Gang Yang ◽  
Jian Hong Yi ◽  
Hong Yan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Grain Boundary ◽  
Eutectic Silicon ◽  
A356 Alloy ◽  
Holding Time ◽  
Test Results ◽  
Modification Effect ◽  
Microstructure And Mechanical Properties ◽  
Stirring Time

Effects of the holding time and the stirring time on the microstructure and mechanical properties of A356 alloy modified by Sc are researched. According to the test results, most of the eutectic silicon phases have changed to the shape of creeping point, dispersed in the grain boundary of α (Al) phase while stirring 1 minute, in which case both the tensile strength and elongation reach the highest, resulting in the best modification effect. The results also indicate that microstructure and mechanical properties of the alloy reach are the best modification effect when the melt is held 15 minute. It can be known that the optimal stirring time is 1 minute and the optimal holding time is 15 minute in the experiment condition of the work.

Effect of Fast Annealing on Microstructure and Mechanical Properties of Non-Oriented Al-Si Low C Electrical Steels

2007 ◽  
Vol 560 ◽  
pp. 29-34 ◽  
Author(s):  
Emmanuel Gutiérrez C. ◽  
Armando Salinas-Rodríguez ◽  
Enrique Nava-Vázquez
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
Tensile Tests ◽  
Rate Of Change ◽  
Uniaxial Tensile ◽  
Electrical Steels ◽  
Offset Yield Strength ◽  
Microstructure And Mechanical Properties ◽  
Increasing Temperature

The effects of heating rate and annealing temperature on the microstructure and mechanical properties of cold rolled Al-Si, low C non-oriented electrical steels are investigated using SEM metallography and uniaxial tensile tests. The experimental results show that short term annealing at temperatures up to 850 °C result in microstructures consisting of recrystallized ferrite grains with sizes similar to those observed in industrial semi-processed strips subjected to long term batch annealing treatments. Within the temperature range investigated, the grain size increases and the 0.2% offset yield strength decreases with increasing temperature. It was observed that the rate of change of grain size with increasing temperature increases when annealing is performed at temperatures greater than Ac1 (~870 °C). This effect is attributed to Fe3C dissolution and rapid C segregation to austenite for annealing temperatures within the ferrite+austenite phase field. This leads to faster ferrite growth and formation of pearlite when the steel is finally cooled to room temperature. The presence of pearlite at room temperature decreases the ductility of samples annealed at T > Ac1.

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