The Effect of Grain Refiners for Aluminium Alloy Containing Mn-Ti-Sr Dispersoid

2006 ◽  
Vol 519-521 ◽  
pp. 449-454
Author(s):  
V.T. Vacariu ◽  
Aurelian Buzaianu ◽  
Eugeniu Vasile ◽  
R. Trusca ◽  
Petru Moldovan
Keyword(s):  
Volume Fraction ◽  
Lightweight Design ◽  
High Volume ◽  
Sr Modification ◽  
Fine Grain ◽  
Homogenization Time ◽  
Structural Applications ◽  
Complex Shapes ◽  
Metallic Compounds

The new structural applications of aluminum materials are determined by intelligent lightweight design: the demand of safety, ecology, recycling and by economics. Al-Si alloys allow complex shapes to be cast. Metallurgical a high volume fraction of fine dispersoid which are less about 0.1 microns in size are useful for retaining a fine grain. In the 6061 series of alloys, iron combines with aluminium and silicon to form two types of commune inter-metallic, (beta AlFeSi and alpha AlFeSi).The type of inter-metallic that is present these alloys will have an important bearing on the homogenization time, workability and quality of the surface finish. The microstructure of the as-cast samples was evaluated by electronic microscopy and the morphology of inter-metallic compounds related to the efficiently modification. Mn-Ti-Sr modification of Al-alloys is normally accompanied by an increase in porosity in the casting.

scholarly journals Face Grinding Surface Quality of High Volume Fraction SiCp/Al Composite Materials

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Xu Zhao ◽  
Yadong Gong ◽  
Guiqiang Liang ◽  
Ming Cai ◽  
Bing Han
Keyword(s):  
Friction Coefficient ◽  
Surface Morphology ◽  
Surface Quality ◽  
Volume Fraction ◽  
High Volume ◽  
Spindle Speed ◽  
High Volume Fraction ◽  
Machining Parameters ◽  
Al Composite

AbstractThe existing research on SiCp/Al composite machining mainly focuses on the machining parameters or surface morphology. However, the surface quality of SiCp/Al composites with a high volume fraction has not been extensively studied. In this study, 32 SiCp/Al specimens with a high volume fraction were prepared and their machining parameters measured. The surface quality of the specimens was then tested and the effect of the grinding parameters on the surface quality was analyzed. The grinding quality of the composite specimens was comprehensively analyzed taking the grinding force, friction coefficient, and roughness parameters as the evaluation standards. The best grinding parameters were obtained by analyzing the surface morphology. The results show that, a higher spindle speed should be chosen to obtain a better surface quality. The final surface quality is related to the friction coefficient, surface roughness, and fragmentation degree as well as the quantity and distribution of the defects. Lower feeding amount, lower grinding depth and appropriately higher spindle speed should be chosen to obtain better surface quality. Lower feeding amount, higher grinding depth and spindle speed should be chosen to balance grind efficiently and surface quality. This study proposes a systematic evaluation method, which can be used to guide the machining of SiCp/Al composites with a high volume fraction.

scholarly journals Study on Meso-scale Grinding Surface Roughness and Sub-surface Quality of High Volume Fraction SiCp/Al2024 composites

2021 ◽  
Author(s):  
Guangyan Guo ◽  
Qi Gao ◽  
Quanzhao Wang ◽  
Yuanhe Hu
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
High Volume ◽  
High Volume Fraction ◽  
Aluminum Matrix Composites ◽  
Sic Particles ◽  
Meso Scale

Abstract In order to improve the surface grinding quality of high volume fraction aluminum matrix composites, the cutting tool models with different rake angles are established, the grinding process is simulated, and the material removal mechanism and the broken state of SiC particles are obtained. Through single factor experiment, the 60% volume fraction SiCp/Al2024 composites are ground by diamond grinding rod with 3mm diameter, the surface roughness (Ra) is measured, and the surface and sub-surface quality of SiCp/Al2024 composites with meso-scale grinding is investigated. Meanwhile, the influence mechanism of grinding depth (ap) on surface quality is put forward, and the influence of different grinding depth on the fragmentation of SiC particles in sub-surface layer is discussed, which verifies the correctness of grinding simulation. The relevant research and theoretical model are of great significance to the study of grinding properties of composite materials.

Study on Removal Mechanism and Surface Quality of High Volume Fraction SiCp/Al Composites Based on Meso-scale

2021 ◽  
Author(s):  
Po Jin ◽  
Qi Gao ◽  
Quanzhao Wang ◽  
Wenbo Li
Keyword(s):  
Particle Size ◽  
Surface Quality ◽  
Feed Rate ◽  
Volume Fraction ◽  
High Volume ◽  
Milling Process ◽  
Subsurface Damage ◽  
High Volume Fraction ◽  
Removal Mechanism

Abstract The milling process of SiCp/Al composites with high volume fraction and large particle size has been studied in this paper. The stress and strain distribution of SiC reinforced particles and the removal mechanism of the material are analysed. The effects of milling depth and feed per tooth on surface quality were analysed. The effect of feed per tooth on the thickness of subsurface damage layer is revealed. The results show that in the end milling process of high volume fraction SiCp/Al composites, the blade diameter is larger relative to the particle size, which leads to the main removal forms of particle size: extrusion crushing and rolling crushing. The surface defects of the machined workpiece mainly include cavity, crack and delamination caused by extrusion of aluminum matrix. The surface quality of the machined workpiece can be improved by increasing the milling depth appropriately. The increase of the feed rate of each tooth will lead to the increase of the surface defect of the machined workpiece and the deterioration of the surface quality. When the feed rate per tooth increases from 4 to 8 μm, the thickness of subsurface damage increases from 47.7 to 60.5 μm. It is found that the ratio between the minimum cutting thickness of SiCp/Al composites and the radius of the cutting edge should be less than or equal to 4%.

Xps Studies of Hydrogen and Oxygen Bondinguy Configurations in Hydrogenated Microcrystalline Silicon Materials Produced by Neutron Irradiation

1992 ◽  
Vol 283 ◽  
Author(s):  
Y. C. Koo ◽  
G. C. Weatherly ◽  
R. Sodhi ◽  
S. J. Thorpet ◽  
K. T. Austt
Keyword(s):  
Charge Transfer ◽  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Volume Fraction ◽  
Analytical Electron Microscopy ◽  
Single Crystal Silicon ◽  
High Volume ◽  
Electron Diffraction Data ◽  
Crystal Silicon

ABSTRACTThe bonding of Si atoms in μc-Si:H thin films has been investigated using X-ray photoelectron spectroscopy (XPS) in conjunction with infra-red spectroscopy (IR), secondary ion mass spectroscopy (SIMS) and analytical electron microscopy (TEM/EDX/EELS) data. By using a-Si:H and single crystal silicon as reference samples, structural and hydrogen effects could be assessed, since both a-Si:H and μc-Si:H have a similar concentration of hydrogen based on the N15 hydrogen profiling data, but different structures. On the other hand, single crystal silicon and μc-Si:H both have a diamond cubic structure based on electron diffraction data, but single crystal silicon contains little or no hydrogen except adsorbed at the surface. Based on the XPS and IR data, charge transfer of the Si2p core level towards a deep lying level was observed in the μc-Si:H material. IR measurements snowed a large amount of hydrogen was located in the grain boundaries. The charge transfer is mainly due to a change in the hydrogen bonding configuration. A well bonded oxide is formed in the μc-Si:H material near the surface with an almost complete absence of the Si3+ intermediate oxide state. The presence of a large amount of hydrogen (25 at.%) even at a high volume fraction (70%) of μc-phase may limit the oxidation and promote better oxide formation. The variation of the quality of the oxide/μc interface could be a possible explanation for the different photoluminescence observed by various groups for porous μc-Si material.

Mechanical Properties of MWCNT Modified Syntactic Foams with High Volume Fraction of Glass Microspheres

2014 ◽  
Vol 1000 ◽  
pp. 122-125 ◽  
Author(s):  
Martina Drdlová ◽  
Michal Frank ◽  
Jaroslav Buchar ◽  
Josef Krátký
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Syntactic Foam ◽  
High Volume ◽  
High Volume Fraction ◽  
Syntactic Foams ◽  
Glass Microspheres ◽  
Multi Wall Carbon Nanotubes

The effect of multi-wall carbon nanotubes content on physico-mechanical properties of glass microspheres-epoxy resin syntactic foam was evaluated experimentally. Syntactic foam with high volume fraction of microspheres (70 vol%) was prepared and modified by 1 to 5 vol% of multi-wall carbon nanotubes. The compressive, flexural and impact strength tests were conducted, the load-displacement curves were captured. The quality of dispersion of nanoparticles was evaluated in relation to the mixing procedure using scanning electron microscope observation.

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 176-177
Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Volume ◽  
Precipitate Morphology ◽  
Stress Rupture Life ◽  
Nickel Base ◽  
Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

HOT CORROSION OF CERIA-YTTRIA STABILIZED ZIRCONIA PLASMA SPRAYED THERMAL BARRIER COATING BY EUTECTIC VANDIUM PENTAOXIDE-SODIUM SULFATE

2018 ◽  
Vol 18 (1) ◽  
pp. 182-192 ◽  
Author(s):  
Mohammed J Kadhim ◽  
Mohammed H Hafiz ◽  
Maryam A Ali Bash
Keyword(s):  
Thermal Barrier Coating ◽  
Hot Corrosion ◽  
Monoclinic Phase ◽  
Volume Fraction ◽  
High Volume ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Plan View ◽  
Barrier Coating ◽  
Plasma Sprayed

The high temperature corrosion behavior of thermal barrier coating (TBC) systemconsisting of IN-738 LC superalloy substrate, air plasma sprayed Ni24.5Cr6Al0.4Y (wt%)bond coat and air plasma sprayed ZrO2-20 wt% ceria-3.6 wt% yttria (CYSZ) ceramic coatwere characterized. The upper surfaces of CYSZ covered with 30 mg/cm2 , mixed 45 wt%Na2SO4-55 wt% V2O5 salt were exposed at different temperatures from 800 to 1000 oC andinteraction times from 1 up to 8 h. The upper surface plan view of the coatings wereidentified for topography, roughness, chemical composition, phases and reaction productsusing scanning electron microscopy, energy dispersive spectroscopy, talysurf, and X-raydiffraction. XRD analyses of the plasma sprayed coatings after hot corrosion confirmed thephase transformation of nontransformable tetragonal (t') into monoclinic phase, presence ofYVO4 and CeVO4 products. Analysis of the hot corrosion CYSZ coating confirmed theformation of high volume fraction of YVO4, with low volume fractions of CeOV4 and CeO2.The formation of these compounds were combined with formation of monoclinic phase (m)from transformation of nontransformable tetragonal phase (t').

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