Microstructural Characterization of Al-Zr Alloy with Nano-Sized Grains

2006 ◽  
Vol 326-328 ◽  
pp. 429-432 ◽  
Author(s):  
Il Ho Kim ◽  
C.S. Kim ◽  
K.T. Kim ◽  
Yong Hwan Kim
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Microstructural Characterization ◽  
Control Agent ◽  
Process Control Agent ◽  
Grain Sizes ◽  
Treatment Processes ◽  
The Stability ◽  
Zr Alloy

The mechanical alloying processes was employed to fabricate Al-4at.%Zr alloy with nano-sized grains and very fine Al3Zr compounds. The phase transformations and the stability of the phases formed during mechanical alloying and heat treatment processes were investigated. The grain sizes of the alloys immediately after milling and following the subsequent heat treatment at 550°C were 54.2nm and 106.4nm, respectively. Some of Zr atoms were dissolved into the Al matrix and most of them reacted with hydrogen produced by decomposition of PCA(process control agent) to form ZrH2 during mechanical alloying process. These ZrH2 hydrides decomposed gradually after the heat treatment. Stable Al3Zr with a DO23 structure was formed by heat treatment at temperature of more than 4500C. The hardness of the Al-4at.%Zr alloy was more than two times higher than those of other Al-based alloys.

The Method of Eliminating Banded Structure and the Effects of Banded Structure on the Transverse Properties in 20G Steel

2013 ◽  
Vol 347-350 ◽  
pp. 1171-1175 ◽  
Author(s):  
Bin Wang ◽  
Hong Mei Hu ◽  
Cui Zhou
Keyword(s):  
Heat Treatment ◽  
Grain Size ◽  
Stress Concentration ◽  
Base Metal ◽  
Metallic Inclusion ◽  
Banded Structure ◽  
Grain Sizes ◽  
Fine Grain ◽  
Treatment Processes ◽  
Metallic Inclusions

The transverse properties were inferior to the longitudinal properties for the existence of banded structure in 20G steel. In order to eliminate the banded structure and improve the transverse performance of 20G steel, different heat treatment processes were adopted. The results showed that conventional normalizing could reduce the banded structure and refine the grain sizes. When 20G was heated with 10°C/min heating rated and then held at 920°C for 2h, the banded structure in the steel was almost eliminated and the microstructure was homogeneous with fine grain size, the strength increased by 14%. The non-metallic inclusion and carbide in the microstructure leaded to stress concentration and separation with the base metal. To some extent, heat treatment can improve the distribution and form of non-metallic inclusions.

Synthesis and Characterization of Mnbi Magnetic Alloy via Two Different Processing Routes

2021 ◽  
Vol 875 ◽  
pp. 76-80
Author(s):  
Hifsa Mazhar ◽  
Wilayat Hussain
Keyword(s):  
Heat Treatment ◽  
Melt Spinning ◽  
Treatment Time ◽  
Magnetic Energy ◽  
Microstructural Characterization ◽  
Temperature Phase ◽  
Magnetic Alloy ◽  
Positive Temperature ◽  
Melt Spinning Technique

Manganese bismuth alloy has gained importance due to its rare earth free elements, positive temperature coefficient and unique magnetic properties. Low temperature phase (LTP) MnBi was successfully prepared by arc melting with subsequent heat treatments and melt spinning technique followed by heat treatment for different durations. LTP MnBi formation was confirmed using XRD analysis and microstructural characterization of the samples was done using field emission scanning electron microscope. MnBi with greater LTP amount was formed by melt spinning route when compared with its counter arc melted one. Magnetic energy density of LTP MnBi formed by melt spinning technique with different heat treatment time was studied.

scholarly journals Synthesis and characterization of one-dimensional titanate structure

2008 ◽  
Vol 2 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Ljubica Nikolic ◽  
Marija Maletin ◽  
Paula Ferreira ◽  
Paula Vilarinho
Keyword(s):  
Heat Treatment ◽  
Structural Characteristics ◽  
Hydrothermal Process ◽  
Synthesis And Characterization ◽  
One Dimensional ◽  
Treatment Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Simple Hydrothermal Process

One-dimensional titania structures were synthesized trough a simple hydrothermal process in a highly alkaline conditions. The aim of this work was to elucidate the effect of time on the formation of 1D titanates as well on its structural characteristics (morphology, phase composition, surface area). Apart from that, the effect of heat treatment conditions on the stability of titanate based 1D samples has been investigated. The results have revealed that it is possible to form one-dimensional titanates already after 1 hour of hydrothermal synthesis. Although the composition of titanates is still under debate, the results probably correspond to the layered sodium titanates. The 1D prepared structures show a remarkable stability during heating, remaining the basic morphology and composition even up to 700?C.

Effect of Post Weld Heat Treatment on Al 5052-SS 316 Explosive Cladding with Copper Interlayer

2018 ◽  
Vol 910 ◽  
pp. 35-40
Author(s):  
Eswaran Elango ◽  
Somasundaram Saravanan ◽  
Krishnamorthy Raghukandan
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Intermetallic Compounds ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Post Weld Heat Treatment ◽  
Inclination Angles ◽  
Copper Interlayer ◽  
Weld Heat

This study focuses on effect of post weld heat treatment (PWHT) on interfacial and mechanical properties of Al 5052-SS 316 explosive clad with copper interlayer at varied loading ratios and inclination angles. The use of interlayer is proposed for the control of additional kinetic energy dissipation and to alleviate the formation of intermetallic compounds at the interface. The Al-Steel clads are subjected to PWHT at varied temperatures (300°C-450°C) for 30 minutes and the results are presented. The microstructural characterization of as-clad and PWHT samples is observed by an optical microscope and Scanning Electron Microscope (SEM). Maximum hardness is obtained at the interface of the as-clad and PWHT samples. Increase in PWHT temperature enhances the tensile strength of the composite, whereas, the tensile strength decreases at 300°C due to the diffusion of Al and Cu elements and the formation of detrimental intermetallic compounds.

Effect of Microalloying Elements on Mechanical Properties in the High Strength Low Alloy Steel

2015 ◽  
Vol 830-831 ◽  
pp. 231-233 ◽  
Author(s):  
P.K. Mandal ◽  
Ravi Kant
Keyword(s):  
Mechanical Properties ◽  
Hsla Steel ◽  
High Strength ◽  
Microstructural Characterization ◽  
Strengthening Mechanism ◽  
Treatment Processes ◽  
Heating Treatment ◽  
Secondary Precipitates ◽  
Microalloying Elements

The effect of microalloying elements in Ti-Nb-V containing high strength low alloy (HSLA) steel has been investigated in the present study. The addition of low alloying elements (such as Ti, Nb and V) and distinct heating treatment processes has been used to improve the mechanical properties of HSLA steel. The effect on the microstructure and mechanical properties of normalizing treatment (at 950°C) of as forged steel has been investigated. The microstructural characterization of microalloyed HSLA steel is carried out by using different techniques such as optical microscopy, scanning electron microscopy (SEM) etc. The hardness, tensile testing and Charpy V notch impact tests are performed to study the mechanical behaviour of the alloy. It has been concluded that the precipitation strengthening mechanism for the improvement of impact toughness due to secondary precipitates such as TiN, Ti(C, N), VN etc.

scholarly journals Microstructural characterization of Cu82.3Al8.3Mn9.4 shape memory alloy after rolling

10.30544/314 ◽  
2017 ◽  
Vol 23 (3) ◽  
pp. 281-289
Author(s):  
Mirko Gojić ◽  
Stjepan Kožuh ◽  
Ivana Ivanić ◽  
Magdalena Selanec ◽  
Tamara Holjevac Grgurić ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Cold Rolling ◽  
Shape Memory ◽  
Microstructural Characterization ◽  
Rolling Process ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Hot And Cold Rolling

In this paper, the microstructure of Cu82.3Al8.3Mn9.4 (in wt. %) shape memory alloy after hot and cold rolling was investigated. The Cu82.3Al8.3Mn9.4 alloy was produced by a vertical continuous casting method in the form a cylinder rod of 8 mm in diameter. After the casting, hot and cold rolling was performed. By hot rolling a strip with a thickness of 1.75 mm was obtained, while by cold rolling a strip with a thickness of 1.02 mm was produced. After the rolling process, heat treatment was performed. Heat treatment was carried out by solution annealing at 900 °C held for 30 minutes and water quenched immediately after heating. The microstructure characterization of the investigated alloy was carried out by optical microscopy (OM), scanning electron microscopy (SEM) equipped with a device for energy dispersive spectroscopy (EDS). Phase transformation temperatures and fusion enthalpies were determined by differential scanning calorimetry (DSC) method. The homogenous martensite microstructure was confirmed by OM and SEM micrographs after casting. During rolling the two-phase microstructure occurred. Results of DSC analysis showed martensite start (Ms), martensite finish (Mf), austenite start (As) and austenite finish (Af) temperatures.

Characterization of Ni75Mo25 Alloy Prepared by Mechanical Alloying and Heat Treatment

2013 ◽  
Vol 203-204 ◽  
pp. 394-397
Author(s):  
Joanna Panek ◽  
Bożena Bierska-Piech ◽  
Jolanta Niedbała
Keyword(s):  
Heat Treatment ◽  
Mechanical Alloying ◽  
Weight Ratio ◽  
Milling Process ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Powder Synthesis ◽  
X Ray ◽  
Microscopy Techniques

The process of Ni75Mo25powder synthesis via mechanical alloying (MA) was studied. Process was carried out from pure elements: Ni and Mo with a particle size under 150 μm. A ball-to-powder weight ratio and the rotational speed were 5:1 and 500 rpm, respectively. Oxidation was reduced by milling under an argon atmosphere. The milling process was performed during up to 60 hours. X-ray diffraction (XRD) and scanning electron microscopy techniques have been used to investigate resulting products. It was found that the particle sizes decrease with the increase in milling time. The resulting powder consists of metastable Ni(Mo) and Mo(Ni) solid solutions. Milled Ni75Mo25 powder was subjected to heat treatment at temperature of 773K, 973K and 1173K. As a result of annealing the formation of Ni4Mo and NiMo intermetallic phases was observed.

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