Vickers micro-hardness of solid solution in the system Cr2O3-Al2O3

1980 ◽  
Vol 15 (5) ◽  
pp. 1314-1316 ◽  
Author(s):  
K. Shinozaki ◽  
Y. Ishikura ◽  
K. Uematsu ◽  
N. Mizutani ◽  
M. Kato
2007 ◽  
Vol 539-543 ◽  
pp. 1565-1570 ◽  
Author(s):  
Yoshihisa Harada ◽  
David C. Dunand

The microstructure of ternary Al3(Sc1-yREy) intermetallic compounds (where RE is one of the rare-earth elements La, Ce, Nd, Sm, Eu, Yb or Lu), was investigated as a function of RE concentration for 0<y≤0.75. Alloys with La, Ce, Nd, Sm or Eu additions consist of a L12 phase containing a dendritic second phase with D019 (La, Ce, Nd, Sm) or C11b (Eu) structure. Alloys with Yb or Lu additions show a single L12 phase. The RE solubility limits at 1373 K in the L12-Al3(Sc1-yREy) phase are very low for La, Nd, Ce and Eu (0.08-0.41 at.% or y=0.0032-0.0164), low for Sm (3.22 at.% or y=0.1288) and complete for Yb and Lu. The lattice parameter of the L12 solid-solution increases linearly with RE concentration and the magnitude of this effect is correlated with the atomic size mismatch between Sc and the RE elements. The Vickers micro-hardness of the L12 solid-solution increases linearly with increasing RE concentration.


1998 ◽  
Author(s):  
R. Berriche ◽  
R.K. Lowry ◽  
M.I. Rosenfield

Abstract The present work investigated the use of the Vickers micro-hardness test method to determine the resistance of individual die to cracking. The results are used as an indicator of resistance to failure under the thermal and mechanical stresses of packaging and subsequent thermal cycling. Indentation measurements on die back surfaces are used to determine how changes in wafer backside processing conditions affect cracks that form around impressions produced at different loads. Test methodology and results obtained at different processing conditions are discussed.


2013 ◽  
Vol 631-632 ◽  
pp. 167-171
Author(s):  
Wei Xiang Zhang ◽  
Shuang Min Du

For effective bonding of Magnesium alloy, Cu foil was used as the interlayer to conduct the diffusion bonding experiment of AZ31B alloy. The microstructure and properties of the diffusion bonding joint was analyzed by means of SEM, EDS and micro-hardness tester. Experiment results show that compact bonding joint was obtained at the temperature of 480°C, holding time of 30 minutes, pressure of 10 MPa and the vacuum degree of 1.0×10-2Pa. The bonding joint consists of a interfacial diffusion region which is a mixture of Mg2Cu, MgCu2, and Mg(Cu) solid solution, and the transitional zone which is composed of Mg(Cu,Al) solid solution base and Mg17(Al, Cu)12 phase. Within the bonding joint,the micro-hardness shows a step pattern of increasing, which is well accord with the the microstructural feature of the joint.This trial has prove that using Cu as the interlayer is effective to improve the quality of the AZ31B bonding joint.


2010 ◽  
Vol 638-642 ◽  
pp. 564-569 ◽  
Author(s):  
Takumi Haruna ◽  
Itsuki Shinohara

It has been tried to develop Ti-Ca alloys which demonstrates corrosion resistance in an aqueous fluoride solutions. The Ti-Ca alloys were produced by diffusion-metallizing method. A Ti plate and Ca grains were put in a sealed container of stainless steel. As the container was heated at 1000 oC, Ca was melted and partially vaporized in the inner space. Ca then contacts and permeats into the Ti plate to metallize. In a holding time of 450 h, the alloy surface consisted of two layers, the first was oxide layer and the second was metal layer of about 200 m thick. A Vickers micro hardness of the second layer was quite large, upto about 600 Hv. Evaluation of corrosion resistance for the second layer and the inner part was carried out by electrochemical potentiokinetic method. Test solutions were aqueous fluoride solutions produced with HF and NaF. A concentration of fluoride ion was fixed to 0.024 kmol m-3, and pH of the solution was varied from 3.4 to 4.7. As a result, both Ti and Ti-Ca alloy were passivated under natural immersion condition in the solution of pH 4.7. At pH 3.4, on the other hand, Ti was actively dissolved, but Ti-Ca alloy was still passivated, that means Ti-Ca alloy performs much better corrosion resistance than Ti.


1995 ◽  
Vol 400 ◽  
Author(s):  
A.M. Serventi ◽  
M. Vittori Antisari ◽  
L. Guzman ◽  
A. Miotello

AbstractThe surface modification induced by nitrogen ion implantation on the Al-alloy 7075 has been studied with the aim of understanding the microstructural evolution and the phase separation during the implantation process. 150 keV N2+ ions have been implanted at different temperatures from 373 K to 473 K, with a current density of 5–15 µA/cm2 on previously polished samples. The implanted dose was in the range 1 × 1017 N/cm2 - 5 × 1017 N/cm2. Vickers micro-hardness tests and friction coefficient measurements show a real improvement in the mechanical behaviour of the alloy after the treatment.TEM observations of specimens treated at low temperature with different ion dose have been carried out at 200 kV on cross-sectional samples, prepared by ion beam milling. First results show the presence of small AlN hexagonal precipitates whose evolution is followed as a function of the implanted dose.


2016 ◽  
Vol 840 ◽  
pp. 331-335
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi

Cemented tungsten carbides have been paid much attention due its better mechanical properties with excellent combination of hardness and toughness characteristics. The hard WC particles in the coating provide hardness and wear resistance, while the ductile binder such as Co and Ni contribute to toughness and strength. WC-17wt.% Co and WC-9wt.% Ni powders have been sprayed by the HVOF method to form coatings approximately 300μm and 150μm thick onto AISI 1018 steel substrate. Both coatings have been prepared and supplied by an external vendor. The coatings were examined using optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The hardness of both coatings were also measured using Vickers micro-hardness tester. The microstructure of the coatings has been analyzed and found to consist of WC, brittle W2C phase, metallic W phase, and amorphous binder phase of Co and Ni. It is found that WC-Ni has a higher hardness value compared to WC-Co due to high porosity distribution.


2016 ◽  
Vol 7 (6) ◽  
pp. 605-608
Author(s):  
Vadim Chayevski ◽  
Valerij Zhylinski

The parameters of electrolytic synthesis of Ni-P coatings on steel surface from sulfate-chloride electrolyte have been determinated. The Ni-P alloys consist of separate phases of Ni and Ni3P and solid solution of implementation on the basis of the FCC Ni lattice, when it was deposited from the electrolyte at current density to be more than 7 A/dm2. The coating was formed with continuous globular surface at current density of 5 A/dm2. The globular formations are the Ni3P phase. The obtained at current density of 9 A/dm2 coatings have maximum value of micro¬hardness 430 HV. Darbe buvo nustatyti Ni-P dangų ant plieno paviršiaus elektrolitinės sintezės (iš sulfatinio-chloridinio elektrolito) parametrai. Ni-P lydinių mikrostruktūrą sudaro atskiros Ni ir Ni3P fazės arba nikelio kietasis įterpimo tirpalas, turintis kubinę paviršiaus centruotą gardelę, kai dangos yra nusodinamos iš elektrolito, esant srovės tankiui daugiau negu 7 A/dm2. Kai srovės tankis yra daugiau negu 5 A/dm2, formuojasi ištisinis, rutulinio pobūdžio dangos paviršius. Rutulio formos darinius sudaro Ni3P fazė. Dangos, turinčios didžiausią mikrokietumo reikšmę 430 HV, gautos esant srovės tankiui 9 A/dm2.


2020 ◽  
pp. 123-126
Author(s):  
I.O. Misiruk ◽  
O.I. Tymoshenko ◽  
V.S. Taran ◽  
A.V. Taran ◽  
S.P. Romaniuk ◽  
...  

Multicomponent TiAlCrN and TiAlCrCN coatings were deposited using vacuum arc evaporation technique on AISI 430 stainless steel. The influence of working gas pressure, C/N ratio, bias voltage on the structure and tribomechanical properties of the obtained coatings has been studied. The surface morphology, chemical compound of the coatings obtained under the various conditions has been analyzed by SEM with EDX, XRD, and XRF analysis. The dry wear pad-on-disc tests against 100Cr6 counterbody at 20 N load have been carried out. It was established that Vickers micro-hardness was varied from 26 to 41 GPa depending on deposition parameters.


2011 ◽  
Vol 314-316 ◽  
pp. 236-239
Author(s):  
Xian Ming Sun ◽  
Jian Li ◽  
Gui Rong Yang ◽  
Wen Ming Song ◽  
Ying Ma

The Ni/ZrO2 composite powder was used as raw materials to fabricate the surface infiltrated composite layer on cast steel substrate through vacuum infiltrated casting technology. The microstructure indicated that the infiltrated composite layer included surface composite layer, Ni-based alloying layer and diffusion transition layer. The thickness of diffusion transition layer deceased with the increasing thickness of preform. The surface infiltrated composite layer was composed of ZrO2 ceramic particles, Cr2B and NiB intermetalic compounds as well as Ni-based solid solution. The Ni-based solid solution and Fe-based solid solution was the main composition for diffusion transition layer. The change of micro-hardness of surface infiltrated composite layer presents gradient from surface of infiltrated layer to substrate.


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