Effect of Surface and Grain Boundary on the Reversion of Al-Zn Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 1211-1216
Author(s):  
Keiyu Nakagawa ◽  
Teruto Kanadani
Keyword(s):  
Grain Boundary ◽  
Hardness Test ◽  
Age Hardening ◽  
Micro Hardness ◽  
Zn Alloy ◽  
Vickers Micro Hardness ◽  
Zn Alloys ◽  
Effective Source ◽  
Effect Of Surface

Age-hardening of Al-Zn alloy after quenching develops inhomogeneously due to the effect of surface as a vacancy sink and grain boundary as an easy path. In this study, reversion of the age-hardened Al-Zn alloys, in which ellipsoidal GP zones were formed, was investigated by Vickers micro-hardness test. Ellipsoidal GP zones were reverted more quickly near the surface and grain boundary than in the interior, as spherical GP zones in Al-10%alloy did. It is considered that the surface and grain boundary plays a role of effective source for vacancies, in addition to the interior source such as dislocations, as in the case of the reversion of spherical GP zones.

scholarly journals Mechanical Behavior and Microstructural Analysis of Molybdenum-TZM Alloy Subjected to Different Annealing Temperature

2020 ◽  
Vol 1 (1) ◽  
pp. 25-29
Author(s):  
Muhamad Anas Munawwar Ghazali ◽  
Mohd Azhar Harimon ◽  
Mohammad Sukri Mustapa
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Annealing Temperature ◽  
Microstructural Analysis ◽  
Hardness Test ◽  
Optical Microscope ◽  
Recrystallization Temperature ◽  
Micro Hardness ◽  
Annealing Heat Treatment ◽  
Vickers Micro Hardness

Mo-TZM alloy is one of the most famous economic molybdenum-based alloys. The percentage of chemical composition in mass of Mo-TZM alloy are Mo-0.5Ti-0.08Zr-0.03C. By adding some Titanium and Zirconium so that the mechanical properties and recrystallization temperature of molybdenum has been corresponding improvement. The purpose of this study is to determine the effect of different annealing temperature on mechanical properties of Mo-TZM alloy. The samples will be heated at two different temperature which are 1000 oC and 1300 oC in 1 hour and 40 minutes to change their microstructure behavior. The mechanical properties of the sample like hardness will be analyzed by using Vickers Micro hardness test. The force applied is 4.903 N and Vickers micro hardness number is 0.5 HVN for 10 second. Then to observe the microstructure changes, optical microscope and Scanning Electron Microscope (SEM) is be used. At annealing temperature 1000 oC, it show values of hardness is 249.54 VHN and the grain boundary size is 0.0898mm. While at annealing temperature 1300 oC, it show the lowest values of hardness which is 243.55 VHN and the highest grain boundary size which is 0.1068 mm. By doing annealing heat treatment it will decreases hardness values and increases the size of grain boundary

Evaluation of the Resistance of Individual Si Die to Cracking

1998 ◽  
Author(s):  
R. Berriche ◽  
R.K. Lowry ◽  
M.I. Rosenfield
Keyword(s):  
Thermal Cycling ◽  
Hardness Test ◽  
Mechanical Stresses ◽  
Test Method ◽  
Processing Conditions ◽  
Micro Hardness ◽  
Test Methodology ◽  
Vickers Micro Hardness

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.

The Effect of Heat Treatment on the Long-Term Corrosion Resistance in Er Containing 5083 Cold Rolled Sheets

2014 ◽  
Vol 794-796 ◽  
pp. 199-204 ◽  
Author(s):  
Kun Yuan Gao ◽  
Zuo Ren Nie ◽  
Huang Hui ◽  
Sheng Ping Wen ◽  
Xiao Lan Wu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Grain Boundary ◽  
Mass Loss ◽  
Annealing Temperature ◽  
Hardness Test ◽  
Initial Time ◽  
Micro Hardness ◽  
Nose Temperature

The effect of heat treatment on the long-term corrosion resistance of Er containing 5083 aluminum alloy was studied using the micro-hardness test and mass loss test. The microstructure was analyzed by TEM. To maintain the strength, the annealing temperature was selected to be 100-230°C below the recrystallization onset temperature determined by the micro-hardness test. The plot of the annealing temperature versus the Intergranular Corrosion (IGC) initial time, which is determined by the Nitric Acid Mass Loss Test, showed a C-curve. The shortest IGC initial time (~1h) happened at 175°C, the nose temperature of the C-curve. When annealed at 125-200°C, the samples were IGC sensitive with the initial time less than 3h. The entirely IGC resistant (stabilized) samples were obtained when annealed at 220-230°C. The 175°C sensitized treatment was performed on the 220°C-stabilized samples, which showed that the 3-12h stabilization could significantly improve the resistance for long-term corrosion. TEM results showed that, for the IGC sensitive samples, β phases (Al3Mg2) grew along the grain boundary continuously, while for the stabilized samples, they were isolated on triangle grain boundary and phase boundary.

Effect of an Addition of Silver on the Age Hardening and the Formation of a Soft Surface Layer in an Al-12mass%Zn Alloy

2006 ◽  
Vol 519-521 ◽  
pp. 1883-1888 ◽  
Author(s):  
Teruto Kanadani ◽  
Keiyu Nakagawa ◽  
Norio Hosokawa ◽  
Akira Sakakibara ◽  
Koji Murakami ◽  
...  
Keyword(s):  
Surface Layer ◽  
Grain Boundaries ◽  
Resistivity Measurement ◽  
Hardness Test ◽  
Age Hardening ◽  
Electrical Resistivity Measurement ◽  
Quenching Temperature ◽  
Soft Surface ◽  
Long Time ◽  
Zn Alloy

The aging of Al-Zn alloys has been vastly studied for decades. In the previous paper, 0hta et al. studied carefully the hardness of the alloy during aging and revealed the existence of softer regions near the surface and the grain boundary than the interior of the specimen even after aging for a long time. Electrical resistivity measurement and X-ray small angle scattering experiment together with hardness test suggested that in these regions vacancy decay to the surface and grain boundaries was severe, thus the growth of GP zones were suppressed and therefore age hardening was retarded. Also, it is well-known that an addition of a small amount of Ag raised solvus temperature of GP zones. In this paper, soft surface layer formed in an Al-12mass%Zn alloy is studied by adding small amount of Ag by means of hardness test and resistometry. Addition of Ag more than 0.1% decreases the thickness of soft surface layer as well as accelerates age hardening rate and suppresses the formation of soft region near the grain boundaries. Higher quenching temperature also reduces the thickness of soft surface layer. Together with the behavior of aging curves of the specimen with various thicknesses, the origin of the soft surface layer is confirmed to be the effective role of surface as sinks for vacancies.

Effects of Grain Boundary on Age Hardening and Reversion in Al-Zn Alloys

1983 ◽  
Vol 77 (1) ◽  
pp. K49-K51 ◽  
Author(s):  
M. Ohta ◽  
A. Sakakibara ◽  
H. Yamada ◽  
M. Yamada ◽  
T. Kanadani
Keyword(s):  
Grain Boundary ◽  
Age Hardening ◽  
Zn Alloys

The Role of Zirconium Additions in Recrystallization of Aluminum Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 383-387 ◽  
Author(s):  
Hasso Weiland ◽  
Soon Wuk Cheong
Keyword(s):  
Grain Size ◽  
Aluminum Alloys ◽  
Grain Boundary ◽  
Solute Drag ◽  
Heat Treatments ◽  
Boundary Mobility ◽  
Grain Boundary Mobility ◽  
Structural Applications ◽  
Zn Alloys

Control of grain size during recrystallization of aluminum alloys is critical when tailoring material properties for structural applications. Most commonly the grain size is controlled by adding alloying elements which form second phases during homogenization heat treatments small enough to impose a Zener drag on the grain boundary mobility. These phases are known as dispersoids and are in the 10 to 200 nm in diameter range. In Al-Zn alloys, zirconium has been successfully used in controlling the degree of recrystallization after solution heat treatments. It is commonly understood that the Al3Zr dispersoids of about 20 nm in diameter present in the microstructure are the key features affecting grain boundary mobility. With the success of controlling recrystallization in Al- Zn alloys, zirconium has been added to other alloy systems, such as Al-Cu-Mn, and a similar retarding effect in recrystallization kinetics has been observed as seen in the Al-Zn systems. However, in Al-Cu-Mn alloys, zirconium bearing dispersoids are not observable in the microstructure. Consequently, additional microstructural effects such as solute drag need to be considered to explain the experimental observations. In this paper, the role of zirconium additions in aluminum alloys will be summarized.

Age-Hardening Behavior of Pd-Ag-Sn-In-Zn Alloy

2014 ◽  
Vol 1028 ◽  
pp. 14-19 ◽  
Author(s):  
Hai Jun Wu ◽  
Xiao Qing Zuo ◽  
Ying Wu Wang ◽  
Kun Hua Zhang ◽  
Yu Zeng Chen
Keyword(s):  
Aging Time ◽  
Early Stage ◽  
Energy Dispersive Spectrometer ◽  
Hardness Test ◽  
Age Hardening ◽  
Aged Alloy ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Zn Alloy

Pd-Ag-Sn-In-Zn alloy was subjected to isothermal aging treatments at 400°C, 500°C, and 650°C. Age-hardening behaviour and related microstructure changes of the aged alloy were studied by means of hardness test, X-ray diffraction (XRD), scanning electron microscopic (SEM) and energy dispersive spectrometer (EDS). The results indicate that the hardness of the alloy reaches a highest value of 348Hv after aging at 650°C for 20min. Further increasing the aging time leads to softening. The hardening of the alloy at early stage of the age-hardening at 650°C is ascribed to the formation of lamellar (α1+ β) precipitates along the grain boundaries of α matrix. The softening of the alloy occurred by further increasing aging time is caused by the coarsening of the precipitates.

scholarly journals Morphology and metallurgical studies on a few archeological samples found in old forges in Japan

2013 ◽  
Vol 37 (1) ◽  
pp. 43-50
Author(s):  
AK Das ◽  
I Kamal
Keyword(s):  
Iron Oxides ◽  
Natural Environment ◽  
Hardness Test ◽  
Hardness Measurement ◽  
Spectroscopy Study ◽  
Micro Hardness ◽  
X Ray ◽  
Naked Eye ◽  
Academy Of Sciences ◽  
Vickers Micro Hardness

An investigative study was carried out on a few archeological samples collected from very old and abandoned forges situated near Izumo city of Shimane prefecture in Japan. The samples were named as Koedo Tatara (in Japanese) and identified as Koedo-21, Koedo-39 and so on, as per the number of well dug for hunting the samples. In the naked eye observation the samples were looked like the rusted iron lump of heterogeneous shapes having brownish and blackish colours. A variety of minerals such as ilmenite (FeO.TiO2), fayalite (2FeO.SiO2), hercinite (2FeO.Al2O3) along with ferrite (FeO) were identified by observing the structural morphologies in optical microscopic study. EDS (Energy dispersive X-ray spectroscopy) study revealed that most of the samples were the composite of iron oxides along with a few amount of carbon, silica (SiO2), alumina (Al2O3), rutile (TiO2) etc. Vickers micro-hardness test revealed that several samples were moderately hard and some others were nonmetallic oxides and not fit for hardness measurement. It was realized that the samples were the by-product of old blacksmith’s forges which were dismantled for hundreds of years in the natural environment. DOI: http://dx.doi.org/10.3329/jbas.v37i1.15679 Journal of Bangladesh Academy of Sciences, Vol. 37, No. 1, 43-50, 2013

Effect of Surface on the Reversion of Age-Hardened Al–Zn Alloy and Role of Grain Boundaries

1990 ◽  
Vol 117 (1) ◽  
pp. K19-K21 ◽  
Author(s):  
A. Sakakibara ◽  
T. Kanadani ◽  
M. Yamada ◽  
M. Ohta
Keyword(s):  
Grain Boundaries ◽  
Zn Alloy ◽  
Effect Of Surface

Micro-Hardness and Adhesion of Boron Carbon Nitride Coatings

1997 ◽  
Vol 11 (16n17) ◽  
pp. 749-756 ◽  
Author(s):  
Hou Qingrun ◽  
J. Gao
Keyword(s):  
Carbon Nitride ◽  
Pulsed Laser ◽  
Hardness Test ◽  
Laser Deposition ◽  
Micro Hardness ◽  
Nitride Coatings ◽  
Quartz Substrates ◽  
Boron Carbon Nitride ◽  
Vickers Micro Hardness ◽  
Boron Carbon

Boron carbon nitride coatings have been synthesized by the pulsed laser deposition method. Vickers micro-hardness and adhesion of the coatings were studied. A new model was applied to determine the hardness of the coatings which were too thin to be directly measured by the Vickers micro-hardness test. An intermediate layer of silicon was used to enhance the adhesion of the coatings on stainless steel, glass, and quartz substrates.

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