A study on the phase transformation of BCuAl9Fe4 alloy

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040140
Author(s):  
Anh Tuan Vu ◽  
Duong Nam Nguyen ◽  
Ba Linh Mai ◽  
Khanh Pham Mai
Keyword(s):  
Grain Size ◽  
Phase Transformation ◽  
Intermetallic Phase ◽  
Metallic Phase ◽  
Martensite Phase ◽  
Casting Alloy ◽  
Tem Analysis ◽  
Fine Grain ◽  
Mixture Formula ◽  
The Matrix

This paper’s aim is to describe the results of the phase transformation of BCuAl9Fe4 alloy after casting, quenching and aging. After casting, the microstructure of this alloy consists of [Formula: see text] phase with grain size about 100 [Formula: see text]m, mixture [Formula: see text] and the inter-metallic phase Fe3Al. However, the proportion of the [Formula: see text] phase in the casting alloy is coarse. The alloy was heated at [Formula: see text]C for 2 h then quickly cooling in water. After quenching, the microstructure of alloy shows that the grain size reduced to about 40 [Formula: see text]m. After quenching, the alloy was aged at [Formula: see text]C for 2 h, the martensite phase of this alloy decomposed into order phase ([Formula: see text] with fine grain size, dispersed in the matrix. The intermetallic phase was fine and evenly dispersed in the matrix. By TEM analysis, after heat treatment, the structure of martensite and the inter-metallic phase in this alloy which had small grain size were formed.

Effect of Microcast-X Fine Grain Casting on the Microstructure and Mechanical Properties of K492M Alloy at 760°C

2016 ◽  
Vol 849 ◽  
pp. 549-556
Author(s):  
Pin Pin Hu ◽  
Qi Dong Gai ◽  
Qing Li ◽  
Xin Tang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Rupture Life ◽  
Stress Rupture ◽  
Casting Alloy ◽  
Stress Rupture Life ◽  
Casting Technique ◽  
Conventional Casting ◽  
Fine Grain

The effect of Microcast-X fine grain casting on the microstructure and mechnical property K492M alloy at 760°C of was investigated. The results indicated that Microcast-X fine grain casting decreased grain size and dendrite space of γ′ phase and γ/γ′ eutectic. In addition, the element segregation decreased significantly compared to conventional casting technique. Also, the size and distribution of MC carbide were improved. By Microcast-X fine grain casting, the tensile strength increased from 934MPa of conventional casting alloy to 1089MPa and the elongation increased from 1.9% to 5.7%. In addition, the stress-rupture life increased from 28.8h of conventional casting alloy to 72.5h. And the fracture mechanism for the alloys by Microcast-X fine grain casting is trans-granular fracture toughness.

Jadeite–K-feldspar rocks and jadeitites from northwest Turkey

1997 ◽  
Vol 61 (409) ◽  
pp. 835-843 ◽  
Author(s):  
Aral I. Okay
Keyword(s):  
Grain Size ◽  
Debris Flows ◽  
Bulk Rock ◽  
Rock Composition ◽  
Bulk Rock Composition ◽  
Fine Grained ◽  
Fine Grain ◽  
The Matrix ◽  
Mineral Pair

AbstractBlueschist-facies rocks with jadeite-K-feldspar-lawsonite paragenesis occur as exotic blocks in Miocene debris flows in the blueschist belt of northwest Turkey. The jadeite-K-feldspar rocks have a very fine grain size and although recrystallized locally retain a relict porphyritic volcanic texture. The former nepheline microphenocrysts, recognized from their characteristic shapes, are pseudomorphed by jadeite and K-feldspar, while the relict magmatic aegirine has rims of jadeite. The matrix of the rock consists of very fine-grained aggregates of jadeite, K-feldspar and lawsonite. In some blocks, jadeite makes up >60% of the mode. Jadeite, K-feldspar and lawsonite in the blocks are essentially pure end-member in composition. P-T estimates for these rocks are 8 ± 2 kbar and 300 ± 50°C. The preserved volcanic texture, relict aegirine and the bulk rock composition indicate that these rocks represent metamorphosed phonolites. The paragenesis in these rocks shows that jadeite-K-feldspar is a stable mineral pair in blueschist-facies P-T conditions.

Effect of Grain Size on the Isothermal Oxidation of Fe-33Ni-19Cr Alloys at 700 °C

2013 ◽  
Vol 845 ◽  
pp. 56-60
Author(s):  
Noraziana Parimin ◽  
Esah Hamzah ◽  
Astuty Amrin
Keyword(s):  
Grain Size ◽  
Oxidation Behavior ◽  
Annealing Treatment ◽  
Isothermal Oxidation ◽  
Coarse Grain ◽  
X Ray ◽  
Fine Grain ◽  
The Matrix ◽  
Different Temperatures ◽  
Different Grain Size

The isothermal oxidation behavior of two different grain size of Fe-33Ni-19Cr alloys was investigated at 700 °C in laboratory air. Different grain size of alloyed was made of solution annealing treatment at different temperatures, namely, 1050 °C and 1150 °C for fine and coarse grain, respectively. Optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were employed in this study to analyze the oxidation behavior of solution-annealed samples. Results indicate that the fine grain size solution-annealed alloys possess a better oxidation resistance and reduced oxidation rate than the coarse grain. The differences observed are attributed to the finer grains increasing the relaxation of the oxide scale stress and improving the adhesion of the oxide layer on the matrix.

Microstructure and Mechanical Properties of Quasicrystal Reinforced Magnesium Matrix Composites

2011 ◽  
Vol 686 ◽  
pp. 242-246
Author(s):  
Xu Dong Wang ◽  
Wen Bo Du ◽  
Chao Hui Wang ◽  
Shu Bo Li
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Maximum Yield ◽  
Icosahedral Quasicrystal ◽  
Strengthening Effect ◽  
Magnesium Matrix Composites ◽  
Fine Grain ◽  
Average Grain Size ◽  
The Matrix ◽  
Maximum Yield Strength

Magnesium-based composites reinforced with stable icosahedral quasicrystal particles have been fabricated via Repeated Plastic Working (RPW) process. The microstructure of the composites has been investigated by XRD, SEM, TEM and HREM, and its mechanical properties have also been studied. The results showed that the RPW process could reduce the matrix grain size significantly, and the average grain size of matrix was only about 500 nm after 200 cycles of RPW. A good metallurgical bond interface between the quasicrystal particles and the Mg matrix was found. The composites exhibited the maximum yield strength of 265MPa and the maximum ultimate tensile strength of 309MPa at room temperature, respectively. The enhancement of mechanical properties is attributed to the strengthening effect of the quasicrystal particles and the fine-grain size of matrix.

The Effect of Grain Size and SiC Particulates on the Strength and Ductility of MoSi2

1993 ◽  
Vol 322 ◽  
Author(s):  
Amit K. Ghosh ◽  
Ajoy Basu
Keyword(s):  
Grain Size ◽  
Compression Behavior ◽  
Grain Sizes ◽  
Fine Grain ◽  
Compression Creep ◽  
The Matrix ◽  
Tension And Compression ◽  
Sic Particulates ◽  
Ductile To Brittle Transition ◽  
Strength And Ductility

AbstractMonolithic MoSi2 and MoSi2 reinforced with SiC particulate reinforcements have been produced with widely varying grain sizes. Monotonic compression behavior of these materials has been examined in the temperature range of room temperature to 1200°C. Based on these results, the ductile-to-brittle transition temperature at low deformation rate of MoSi2 and its composite appears to be near 900°C and may decrease slightly with decreasing grain size. Tension and compression creep behavior of these materials were also studied between 1100 and 1400°C. Creep strength of the matrix decreases with decreasing grain size even in the nominally dislocation climb-glide regime. While 20 vol% SiC particulates provide a reasonable amount of creep strengthening of the fine grain MoSi2 matrix, strengthening due to coarser grain size can be significantly higher in these materials. These results parallel those on other intermetallics.

Study on CO2 Laser Surface Hardening of 17-4PH Stainless Steel

2011 ◽  
Vol 239-242 ◽  
pp. 73-76
Author(s):  
Jun Wei Zhang ◽  
Gang Lei ◽  
Shu Chen Pan ◽  
Fa Yu Wu
Keyword(s):  
Stainless Steel ◽  
Phase Transformation ◽  
Aging Treatment ◽  
Secondary Phase ◽  
Hardened Layer ◽  
Laser Surface ◽  
Transformation Zone ◽  
Fine Grain ◽  
The Matrix ◽  
Surface Quenching

At present work, the microstructure and corresponding hardness of 17-4PH stainless steel were investigated by the process of CO2 laser surface quenching and aging treatment. The hardness of the phase transformation zone in the hardened layer was 433.2HV, higher than 378.1HV of the matrix, which was attributed to the fine-grain and solution strengthening after laser quenching. The hardness of the phase transformation zone increased further to 464.5HV after an aging treatment at 520°C due to the precipitation strengthening of fine secondary phase particles.

The Behavior of Phase Transformation Characteristics and Ageing on Alloying Method of CuZnAl Shape Memory Alloy

2007 ◽  
Vol 544-545 ◽  
pp. 487-490
Author(s):  
Gon Seung Yang ◽  
Jung Il Lee ◽  
Woo Yang Jang
Keyword(s):  
Grain Size ◽  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Brittle Fracture ◽  
Shape Memory ◽  
Void Formation ◽  
Solution Treatment ◽  
Martensite Phase ◽  
Β Phase ◽  
Misch Metal

The effect of transformation temperature and phase transformation characteristics by alloying method of CuZnAl shape memory alloy with a small of misch metal and Zr contents were investigated. The addition of misch metal and Zr was very effective for reducing the grain size. After solution treatment, the specimens were post-quench aged or step quenched at 373K to 623K for variation of hardness value. It was found that the hardness value was very increased at 473K and 523K. The fracture mode has been changed from trans granular brittle fracture to ductile fracture with void formation and coalescence by the addition of misch metal and Zr. Ageing of the β-phase decreased the Ms temperature, but that of the martensite phase increases the As temperature. The change in As temperature with post-quench aging can be attributed to recovery of order in the β-phase.

scholarly journals In situAl3Ti–Al2O3 intermetallic matrix composite: Synthesis, microstructure, and compressive behavior

2000 ◽  
Vol 15 (9) ◽  
pp. 1943-1949 ◽  
Author(s):  
H. X. Peng ◽  
Z. Fan ◽  
D. Z. Wang
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Matrix Composite ◽  
Ti Alloy ◽  
Compressive Behavior ◽  
Fine Grain ◽  
Intermetallic Matrix ◽  
Intermetallic Matrix Composite ◽  
The Matrix

A fully dense in situ Al3Ti–Al2O3 intermetallic matrix composite containing about 30 vol% Al2O3 particles was prepared by combining squeeze casting with combustion synthesis using the chemical reaction between TiO2 and Al. The microstructure of the in situ composite was examined using x-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques. Compressive behavior of the composite was investigated in the temperature range of 25–600 °C and compared with that of the as-cast Al3Ti alloy. The in situ formed spherical α–Al2O3 particles with a size of 0.2–1 μm were uniformly distributed in the Al3Ti matrix. The grain size of the Al3Ti matrix containing a small amount of Al2Ti precipitate was 2–10 μm. The compressive strength of the in situ composite was about 6–9 times that of the as-cast monolithic Al3Ti alloy and could be maintained at temperatures up to 600 °C. This was mainly attributed to the fine grain size of Al3Ti matrix and the rule of mixture strengthening of Al2O3 particles. The existence of Al2Ti phase and high dislocation density in the matrix also contributed positively to the composite strength.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

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