Stability of SiC in Al-Rich Corner of Liquid Al-Si-Mg System

2005 ◽  
Vol 473-474 ◽  
pp. 415-420 ◽  
Author(s):  
Maziar Sahba Yaghmaee ◽  
György Kaptay
Keyword(s):  
Solid Solution ◽  
Composite Materials ◽  
Aluminium Alloy ◽  
Thermodynamic Analysis ◽  
Magnesium Content ◽  
Liquid Aluminium ◽  
Working Temperature ◽  
Si Content

The thermodynamic analysis of the SiC/Al-Si-Mg system has been performed in order to find the conditions to produce SiC/Al-Si-Mg composite materials with the stable SiC/alloy interface (for both a-SiC and b-SiC) and with the solidification of primary a-Al solid solution. The conditions to avoid the formation of Al4C3 are expressed as function of temperature, and the silicon and magnesium content of the liquid aluminium alloy. It has been shown that to ensure stabilization of (the more stable) b-SiC, lower Si-content is needed and higher working temperature is allowed, compared to the requirements to stabilize (the less stable) a-SiC.

scholarly journals Alkalinity–silicon ratio as an assessment factor for the efficiency of silicate slags in wetland rice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thoppil Sreenivasan Sandhya ◽  
Nagabovanalli Basavarajappa Prakash
Keyword(s):  
Silicon Content ◽  
Chemical Properties ◽  
Magnesium Content ◽  
Wetland Rice ◽  
Agronomic Efficiency ◽  
Economic Production ◽  
Incubation Experiments ◽  
Calcium And Magnesium ◽  
Si Content ◽  
Assessment Factor

AbstractSilicate slags are one of the most widely used silicon (Si) source in agriculture. Even though the agronomic significance of slags has been demonstrated in several crops, only a few attempts were made to evaluate these Si sources based on their chemical composition. The main objective of this study was to characterize different silicate slags based on their chemical properties and to explore the effect of these chemical properties on the yield, and Si uptake in wetland rice, and dissolution of Si into the soil. Slags were characterised for pH, calcium and magnesium content (alkalinity, A), silicon content, 5 day Na2CO3 + NH4NO3 extractable Si content, and alkalinity to Si ratio (A/Si). Greenhouse and incubation experiments were also conducted using different silicate slags and wollastonite applied at the rate of 300 kg Si ha−1. Slags with A/Si < 3 were found to be ideal Si sources for the economic production of wetland rice and found consistent in increasing soil Si content and rice Si uptake. We conclude that the A/Si ratio of slags can be used as an important parameter to assess the agronomic efficiency of silicate slags in wetland rice.

Accumulative Roll Bonding of 7075 Aluminium Alloy at High Temperature

2010 ◽  
Vol 638-642 ◽  
pp. 1929-1933 ◽  
Author(s):  
P. Hidalgo ◽  
C.M. Cepeda-Jiménez ◽  
O.A. Ruano ◽  
F. Carreño
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Aluminium Alloy ◽  
Accumulative Roll Bonding ◽  
Dynamic Recovery ◽  
Rolling Texture ◽  
Al Alloy ◽  
Roll Bonding ◽  
Fibre Texture ◽  
Grain Sizes

The 7075 Al alloy was processed by accumulative roll bonding (ARB) at 300, 350 and 400 °C. The microstructure and texture were characterized and the hardness was measured. Cell/(sub)grain sizes less than 500 nm and typical β-fibre rolling texture were observed in the three ARBed samples. At 400 °C, the presence of elements in solid solution leads to a poorly misoriented microstructure and to a homogeneous β-fibre texture. At 300 and 350 °C highly misoriented microstructure and heterogeneous β-fibre rolling texture are observed, especially at 350 °C, wherein the degree of dynamic recovery is higher. Hardness of the ARBed samples is affected by the amount of atoms in solid solution at the different processing temperatures.

Combustion co-synthesis of Si3N4-based in situ composites

1996 ◽  
Vol 11 (12) ◽  
pp. 2968-2970 ◽  
Author(s):  
J. T. Li ◽  
W. S. Liu ◽  
Y. L. Xia ◽  
C. C. Ge
Keyword(s):  
Solid Solution ◽  
Silicon Carbide ◽  
Silicon Nitride ◽  
Thermodynamic Analysis ◽  
Experimental Results ◽  
Titanium Carbonitride ◽  
In Situ Composites

The feasibility of synthesizing silicon nitride-silicon carbide-titanium carbonitride composites by combustion reactions is demonstrated. With titanium carbonitride taken to be an ideal solid solution, its composition is determined as TiC0.36N0.64. Thermodynamic analysis supports the experimental results.

The Influence of Heat Treatment on Corrosion Resistance of PM Composite Materials Based on EN AW-AlCu4Mg1(A) Aluminium Alloy Reinforced with the Ti(C,N) Particles

2007 ◽  
Vol 534-536 ◽  
pp. 845-848 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Anna Włodarczyk-Fligier ◽  
Marcin Adamiak
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Materials ◽  
Aluminium Alloy ◽  
Precipitation Hardening ◽  
Pure Aluminium ◽  
Corrosion Wear ◽  
Alloy Base ◽  
The Matrix ◽  
Base Composite

Investigation results of the heat treatment effect on the corrosion resistance of the EN AW-AlCu4Mg1 (A) aluminium alloy base composite materials reinforced with the Ti(C,N) particles with varying volume fractions are presented. Examinations were made of the EN AW-Al Cu4Mg1(A) aluminum alloy, and also of the composite materials with the matrix from this aluminium alloy. It was found out, basing on own research, that corrosion wear after the corrosion tests of the composite materials with the addition of 5% of the Ti(C,N) particles is smaller compared to the pure aluminium alloy. Precipitation hardening causes improvement of the corrosion resistance of the investigated composite materials and - like in the state before the heat treatment, materials with 5% portion of the Ti(C,N) reinforcement ratio are characteristic of more advantageous features compared to the material without the reinforcement.

scholarly journals Properties of „In Situ” 7475 Alloy Matrix Composites Reinforced Al3Ti Intermetalic Compound Extruded in Semi-Solid State

2016 ◽  
Vol 61 (1) ◽  
pp. 433-438 ◽  
Author(s):  
W. Szymański
Keyword(s):  
Heat Treatment ◽  
Solid State ◽  
Aluminium Alloy ◽  
Extrusion Process ◽  
Liquid Aluminium ◽  
Alloy Matrix ◽  
Electron Microscopies ◽  
Semi Solid ◽  
Composite Hardness

Studies were conducted to improve the mechanical properties of composites based on 7475 aluminium alloy reinforced with Al3Ti particles fabricated by the “in situ” process. The first step involved “dissolving” of titanium in the liquid aluminium alloy and fabricating in this way composite materials with different content of the reinforcing phase (15-45wt%). A relationship between the composite hardness and content of the reinforcing phase was confirmed. The second step involved the improvement of cohesion between the reinforcing particles and composite matrix. By extrusion of samples in semi-solid state, an average increase in hardness by 15-20% relative to the unextruded composite was obtained. In the third step, the fabricated composite was subjected to a heat treatment corresponding to the state T6 in 7475 alloy, which raised the hardness by about 30%. Structure examinations carried out by means of optical microscopy and scanning electron microscopies as well as the results of hardness measurements were described. They enabled estimating the effect of the content of produced Al3Ti particles, and of the extrusion process in semi-solid state and heat treatment parameters on the composite properties. In compression test, the yield strength and compressive strength of the heat-treated composites were determined.

Effect of Different Cooling Rate on the Freezing Behavior of TiB2/A356 Composite

2014 ◽  
Vol 1053 ◽  
pp. 157-164
Author(s):  
Xiu Chuan Wu ◽  
Yu Tao Zhao ◽  
Song Li Zhang ◽  
Kang Le Tian
Keyword(s):  
Composite Materials ◽  
Cooling Rate ◽  
Eutectic Silicon ◽  
Tensile Fracture ◽  
Size Refinement ◽  
Reinforced Composite ◽  
Average Grain Size ◽  
Eutectic Si ◽  
Si Content ◽  
Particle Reinforced Composite

The microstructure and tensile properties of TiB2particles reinforced A356 composite materials at different cooling rates are investigated. Experimental results show that the composition of the alloy solidification ,eutectic silicon content , morphology and size have undergone significant changes while the cooling rate increased: On one hand, α-phase grains significantly reduced, by a 50 μm average grain size refinement to 1~5μm with the evolution from coarse dendritic to rosette dendritic, or even spherical evolution; On the other hand, eutectic Si content increases, and diameter, aspect ratio also showed a decreasing trend, while the circularity is gradually increasing. Meanwhile, with the increasing of cooling rate, the particle distribution of TiB2/A356 particle reinforced composite materials can be optimized. Particle aggregation is reduced, as a result TiB2particles’ reinforcement is more obvious, and the tensile fracture shows the obvious characteristics of ductile fracture.

Role of Halloysite Nanoparticles and Milling Time on the Synthesis of AA 6061 Aluminium Matrix Composites

2014 ◽  
Vol 939 ◽  
pp. 84-89 ◽  
Author(s):  
Leszek Adam Dobrzański ◽  
Błażej Tomiczek ◽  
Grzegorz Matula ◽  
Klaudiusz Gołombek
Keyword(s):  
Composite Materials ◽  
Mechanical Alloying ◽  
Aluminium Alloy ◽  
Matrix Material ◽  
High Energy ◽  
Halloysite Nanotubes ◽  
Composite Powders ◽  
Alloy Matrix ◽  
Reinforcing Particles ◽  
Aluminium Alloy Matrix

The aim of this work is to determine the effect of a reinforcing phase and manufacturing conditions on the structure and properties of newly developed nanostructural powders of composite materials with the aluminium alloy matrix reinforced with natural halloysite nanotubes. Composite materials were manufactured employing as a matrix the air atomized powders of AA 6061 aluminium alloy and as a reinforcement the halloysite nanotubes. Composite powders of aluminium alloy matrix reinforced with 5, 10 and 15 wt.% of halloysite nanotubes were fabricated by high-energy mechanical alloying using a planetary mill. Elaborated composite powders were characterized for their apparent density, microhardness, particle size distribution and microstructure. A structure of newly developed nanostructured composite materials reinforced with halloysite nanotubes prove that a mechanical alloying process allow to improve the arrangement of reinforcing particles in the matrix material. A homogenous structure with uniformly arranged reinforcing particles can be achieved by employing reinforcement with halloysite nanotubes if short time of mechanical alloying is maintained thus eliminating an issue of their agglomeration.

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