Stress Condition for Healing the Crack between the Inclusion and the Matrix Metal in Heavy Forgings

2014 ◽  
Vol 50 (22) ◽  
pp. 84
Author(s):  
Yunlai REN
Keyword(s):  
Stress Condition ◽  
Matrix Metal ◽  
The Matrix

Effect of pouring temperature on A356-TiB2 MMCs cast in sand and permanent moulds by in-situ method

2016 ◽  
Vol 25 (5-6) ◽  
pp. 165-169
Author(s):  
C. Rajaravi ◽  
P.R. Lakshminarayanan
Keyword(s):  
Evaluation Studies ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
Matrix Composites ◽  
Structure Property ◽  
Pouring Temperature ◽  
Matrix Metal ◽  
Property Evaluation ◽  
The Matrix

AbstractThe paper describes a different condition of pouring temperature by sand and permanent mould to produce A356-6 wt% TiB2 metal matrix composites by in-situ method salt metal reaction route. The observation of SEM micrographs shows particle distribution of the TiB2 and it appears in hexagonal shape in Al matrix. The results of X-ray diffraction (XRD) analysis confirmed the formation of those TiB2 particulates and the results showed TiB2 particles are homogeneously dispersed throughout the matrix metal. Subsequent structure-property evaluation studies indicated sub-micron size reinforcement of in-situ formed TiB2 particles with improved physical and mechanical properties as compared to sand and permanent mould of Al-TiB2 composites. From, the permanent mould Al-TiB2 composite has an advantage of increase the properties over sand mould Al-TiB2 composite.

Preparation and Wear Properties of (Al3Zr+ZrB2)P/2124 Composites Material with In Situ Process

2012 ◽  
Vol 616-618 ◽  
pp. 1736-1740
Author(s):  
Lei Jiao ◽  
Yu Tao Zhao ◽  
Zhong Zhong Zhang ◽  
Yan Wei Yang ◽  
Ming Rui Zhang
Keyword(s):  
Magnetic Field ◽  
Composite Materials ◽  
Sliding Friction ◽  
Testing Machine ◽  
Test Methods ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Matrix Metal ◽  
The Matrix

With pulse magnetic field, it is use 2124-K2ZrF6-KBF4 as matrix metal to produce chemical reaction to gain (Al3Zr+ZrB2) p/2124 composite materials in this paper. In this paper, For the sake of researching the microstructure, the morphology, the size and the matrix distribution characteristics of the reinforced grain of prepared composite material , those test methods are used, such as optical microscopy, scanning electron microscope, X-ray diffraction analysis and so on. We will research the magnetic field strength how to influence size and distribution of Al3Zr +ZrB2 particle and the abrasion performance of (Al3Zr+ZrB2)P/2124 composite materials in the room temperature. Wear experiment is proceeding in the CETR UMT 3-V the testing machine and sliding friction is friction way with pin-disc but without lubricant, then analyzes the wear mechanism.

Al2O3-TiC/Fe Functionally Gradient Material Prepared by SHS Casting

2011 ◽  
Vol 704-705 ◽  
pp. 6-10
Author(s):  
Wan Hong Zang ◽  
Chang Lun Yuan ◽  
Yan Li
Keyword(s):  
Gradient Material ◽  
Matrix Metal ◽  
Exterior Surface ◽  
Gradient Distribution ◽  
Functionally Gradient Material ◽  
Surface Composite ◽  
Functionally Gradient ◽  
High Temperature Synthesis ◽  
The Matrix ◽  
Shs Casting

Al2O3-TiC particles reinforced iron matrix functionally gradient material is successfully fabricated by combining the methods of self-propagating high-temperature synthesis (SHS) with casting. The SHS products are analyzed by SEM and XRD and EDS. The results show that the grain size of the particle is round 1μm~3μm, the composition of the Al2O3-TiC/ Fe surface composite takes on a gradient distribution from outside to inside, and transforms gradually to the matrix metal. The hardness below 0.5mm from exterior surface of the functionally gradient materials increases dramatically and gradually changes to the hardness of the matrix. Key words: In situ generation; SHS; Casting; Surface composite material; FGM

Effect on Microstructure and Hardness of Plunger Piston of Fe-Based Composite Coating by Laser Cladding

2011 ◽  
Vol 189-193 ◽  
pp. 830-833
Author(s):  
Yong Tao Zhao ◽  
Wen Xue Li ◽  
Jun Wei Zhou
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Second Phase ◽  
Micro Hardness ◽  
Hardness Testing ◽  
Matrix Metal ◽  
Cladding Layer ◽  
Hard Particles ◽  
The Matrix ◽  
Metal Microstructure

The laser cladding of Fe power technology was used to repair worn plunger piston surface. The microstructure of cladding layer, binder course and the matrix were observed by OM and SEM. Besides, the micro-hardness of different zones was measured through micro-hardness testing. The results show that the matrix metal microstructure of plunger piston is made of ferrite and austenite. By laser cladding Fe-based power on base metal, the cladding layer grain is fine and uniform, grain growth has obvious direction and finally become dendrites oriented, the microstructure of cladding layer is both second-phase hard particles and Fe-based solutes. The combination between matrix and cladding layer is smooth, belong to metallurgy bonding. The hardness of cladding layer is higher than that of other parts in three parts, the max value of micro-hardness is about 1250HV, it can agree with wear resistance need of plunge piston surface.

Mechanism of the Strain Rate Effect of Metal Foams with Numerical Simulations of 3D Voronoi Foams during the Split Hopkinson Pressure Bar Tests

2015 ◽  
Vol 12 (04) ◽  
pp. 1540010 ◽  
Author(s):  
B. Yang ◽  
Z. J. Liu ◽  
L. Q. Tang ◽  
Z. Y. Jiang ◽  
Y. P. Liu
Keyword(s):  
Strain Rate ◽  
Numerical Simulations ◽  
Strain Rate Sensitivity ◽  
Split Hopkinson Pressure Bar ◽  
Rate Sensitivity ◽  
Metal Foams ◽  
Hopkinson Pressure Bar ◽  
Matrix Metal ◽  
The Matrix ◽  
Pressure Bar

With the demand of lightweight structure, more and more metal foams were employed as impact protection and efficient energy absorption materials in engineering fields. But, results from different impact experiments showed that the strain rate sensitivity of metal foams were different or even controversial. In order to explore the true hiding behind the controversial experimental data about the strain rate sensitivity of metal foams, numerical simulations of split Hopkinson pressure bar (SHPB) tests of the metal foams were carried out by finite element methods. In the analysis, cell structures of metal foams were constructed by means of 3D Voronoi, and the matrix metal was assumed to be no strain rate sensitivity, which helps to learn the strain rate effects quantitatively by the foam structures. Numerical simulations showed that the deformation of the metal foam specimen is not uniform during the SHPB tests along the specimen, and the strain–stress relations of the metal foams at two ends of the specimen are different; there exists strain rate sensitivity of the metal foams even the matrix metal has no strain rate sensitivity, when the strain of the metal foams is defined by the displacement difference between the ends of the specimen; localized deformation of the metal foams and the inertia effect of matrix metal are the two main contributions to the strain rate sensitivity of the metal foams.

INFERENCE OF ELECTRON CONFIGURATION AND ACTIVATION ENERGY OF SOLUTE ATOMS IN COPPER AND SILVER CONDUCTORS ON ELECTROMIGRATION VOID FORMATION

2002 ◽  
Vol 16 (09) ◽  
pp. 299-307 ◽  
Author(s):  
A. ZEHE ◽  
A. RAMÍREZ
Keyword(s):  
Chemical Nature ◽  
Void Formation ◽  
Coulomb Repulsion ◽  
Electron Configuration ◽  
Matrix Metal ◽  
Silver Alloys ◽  
Valence Electrons ◽  
The Matrix ◽  
Solute Atoms ◽  
Kinetics Of

It is shown that the kinetics of vacancy coagulation to macroscopic erosion voids in dilute crystalline metallic alloys depends strongly on the chemical nature of the solute element. In numerous published and the author's own electromigration data, it was found that the formation of erosion voids is suppressed if valence electrons of the matrix metal atom and the alloying (or impurity) atom sum up to an odd number. This is due to the formation and electronic charging state of vacancy-impurity pairs. Provided that activation energies of the solute elements are low compared to those of matrix atoms, stable vacancy-impurity pairs dominate and resist coagulation. At higher temperatures the number of pairs diminishes, weakening the mechanism of mutual Coulomb repulsion. Dilute copper and silver alloys are compared in the framework of the mentioned properties, giving copper a better chance for electromigration resistance than silver.

The Metallization of Diamond Grits

2007 ◽  
Vol 534-536 ◽  
pp. 1137-1140
Author(s):  
James C. Sung ◽  
Shao Chung Hu ◽  
Yen Shuo Chang
Keyword(s):  
Nickel Alloy ◽  
Metal Powder ◽  
Metal Matrix ◽  
Metallurgical Process ◽  
Matrix Metal ◽  
Metal Coatings ◽  
The Poor ◽  
Powder Metallurgical Process ◽  
Diffusion Bonds ◽  
The Matrix

Diamond grits in tools are typically held in a sintered matrix of metal powder (e.g. Co). The bonding between diamond and the matrix is essentially mechanical. As a result, most diamond grits are easily knocked out from the tool during cutting. The diamond industry has designed various metal coatings (e.g. Ti, Cr, Si) to improve the adherence of diamond grits in the matrix, but the improvements have been modest (e.g. up to 50% increase of tool life). A revolutionary “Active Braze Coated Diamond” (ABCD) is now being developed. The coating of ABCD is much thicker (e.g. 20 microns) than conventional ones (about 1 micron). The molten braze is wetted and reacted with diamond to form strong chemical bond at the interface so that the diamond does not become knocked out of tools. ABCD is coated with a nickel alloy that can form metallurgical diffusion bonds readily with the metal matrix of the tool. In essence, ABCD turns diamond into a metal grain so that the diamond tools can be made by conventional powder metallurgical process without being concerned about the poor bonding between matrix metal powder and the diamond as before.

Appearance of the Mechanical Plating Formed by Zn-Al Compounding Flake Powders and its Anticorrosion

2009 ◽  
Vol 79-82 ◽  
pp. 811-814 ◽  
Author(s):  
Jie Lu
Keyword(s):  
Corrosion Resistance ◽  
Fracture Surface ◽  
Cross Section ◽  
Corrosive Medium ◽  
Spherical Particles ◽  
Small Space ◽  
Matrix Metal ◽  
Aluminum Oxidation ◽  
The Matrix ◽  
Flake Structure

In this study, a comparison of appearance surface and fracture surface of mechanical plating was made, respectively formed by spherical Zn powders and Zn-Al compounding flake powders. It is found that the spherical particles are deposited and embedded on Zn plating. The deformation of granular Zn powders on coating superficial is relatively large, but there is little distortion of globe grain inside the coating, mainly with spheroidicity distorted. Besides, there are obvious gaps between the particles in Zn coating. In contrast, the flake structure granules of Zn-Al plating are densely and compactly laid out with small space. After contacting with air, the plating coat expands owing to aluminum oxidation, leading to the higher position of the plating coat on the cross section than the matrix metal. We then did salt mist test to verify the corrosion resistance of Zn-Al compounding flake coating. It was found that the Zn-Al compounding flake coating was superior to that formed by globe Zn powder. Results show that the addition of layers of flakes has a better shielding action resisting corrosive medium, leading to the decrease of the osmosis from corrosive medium to the coatings. And the coating can repair naturally after being damaged. We further passivate plating with molybdate to improve the anticorrosion of the coating.

Research on Laser Brazing Applying Al-Based Amorphous Ribbon

2016 ◽  
Vol 849 ◽  
pp. 95-99
Author(s):  
Jing Hui Song
Keyword(s):  
Aluminum Alloy ◽  
Melt Spinning ◽  
Amorphous Ribbon ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Laser Brazing ◽  
Matrix Metal ◽  
Binding Effect ◽  
Hardness Tester ◽  
The Matrix

The Al-based amorphous ribbons were prepared by the copper roller melt spinning method, and then the laser brazing was carried out between aluminum alloy and aluminum alloy. Subsequently, the Micro Vickers Hardness Tester, Metallographic Microscope, Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) were used to characterize the hardness, morphology, micro structure and composition distribution of the welded joints respectively, so as to analyze the structural characteristic, performance characteristic and binding effect of the matrix metal joints. The results indicate that the prepared Al-based amorphous ribbon is of amorphous structure, the soldering point between aluminum alloy and aluminum alloy is well-connected and the joint’s hardness is identical to that of the base metal. The connection between the metal sheets can be achieved by using Al-based amorphous ribbon as solder, which could provide concrete references for the development and application of amorphous brazing in various fields.

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