scholarly journals Role of Ti3AlC2 MAX phase on characteristics of in-situ synthesized TiAl intermetallics. Part II: Phase evolution

2021 ◽  
Vol 1 (4) ◽  
pp. 211-216
Author(s):  
Maryam Akhlaghi ◽  
Esmaeil Salahi ◽  
Seyed Ali Tayebifard ◽  
Gert Schmidt
Keyword(s):  
Crystallite Size ◽  
Rietveld Refinement ◽  
Phase Evolution ◽  
Xrd Analysis ◽  
Max Phase ◽  
Max Phases ◽  
Weight Percentage ◽  
Refinement Method ◽  
Xrd Patterns

In this research, the 2nd part of a series of papers on the processing and characterization of TiAl–Ti3AlC2 composites, the phase evolution during the manufacturing process was investigated by X-ray diffraction (XRD) analysis and Rietveld refinement method. Metallic Ti and Al powders with different amounts of previously-synthesized Ti3AlC2 additives (10, 15, 20, 25 and 30 wt%) were ball-milled and densified by spark plasma sintering (SPS) under 40 MPa for 7 min at 900 °C. Before the sintering process, XRD test verified that the powder mixtures contained metallic Ti and Al as well as Ti3AlC2 and TiC (lateral phase synthesized with Ti3AlC2) phases. In the sintered composites, the in-situ synthesis of TiAl and Ti3Al intermetallics as well as the presence of Ti3AlC2 and the formation and Ti2AlC MAX phases were disclosed. The weight percentage of each phase in the final composition of the samples and the crystallite size of different phases were calculated by the Rietveld refinement method based on the XRD patterns. The size of Ti3AlC2 crystallites in sintered samples was compared with the crystallite size of synthesized Ti3AlC2 powder.

Surface Energy and Crystallite Size Comparisons by Applying Direct Current and Pulse Direct Current on Substrate Bias in PVD Process

2013 ◽  
Vol 315 ◽  
pp. 98-102
Author(s):  
H. Hanizam ◽  
Md Nizam Abd Rahman ◽  
Noraiham Mohamad ◽  
A.R. Soufhwee
Keyword(s):  
Surface Energy ◽  
Crystallite Size ◽  
Direct Current ◽  
Substrate Surface ◽  
Film Coating ◽  
Xrd Analysis ◽  
Substrate Bias ◽  
X Ray Diffraction ◽  
Adhesion Failure

Surface morphology homogeneity and energy modifications for in situ PVD process are two critical factors to prevent unexpected adhesion failure during machining or service. Unlike during film depositing, there is still much gap to be explored on applying pulsed biasing concepts to the substrate during in situ, to ensure the substrate surface readiness prior to film coating. The purpose of this paper is to study the effects of conventional direct current (DC) and pulse direct current (PDC) applied at substrate bias to the surface energy and crystallite size. Tungsten carbide (WC) cutting tool insert and titanium nitride (TiN) were used as substrate and hard coating respectively. The runs were conducted to compare the bias at DC (-500V) and PDC (-200V, -500V, -800V). The surface energy and crystallite size were characterized through wettability test and X-ray diffraction (XRD) analysis. The applying of PDC on the substrate bias was found to further enhance the characteristics of the surface compared to the conventional DC substrate bias.

scholarly journals Understanding Thermodynamic and Kinetic Stabilization of FeNiZr via Systematic High-Throughput In Situ XRD Analysis

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 482
Author(s):  
Efraín Hernández-Rivera ◽  
Sean J. Fudger ◽  
B. Chad Hornbuckle ◽  
Anthony J. Roberts ◽  
Kristopher A. Darling
Keyword(s):  
Statistical Approach ◽  
Xrd Analysis ◽  
Quantitative Information ◽  
Transfer Model ◽  
In Situ Xrd ◽  
Flow Through ◽  
Xrd Patterns ◽  
Powder Compacts

The role of kinetically and thermodynamically driven microstructural evolution on FeNiZr was explored through in situ XRD analysis. A statistical approach based on log-likelihoods and composite link model was used to fit and extract important data from the XRD patterns. Best practices on using the statistical approach to obtained quantitative information from the XRD patterns was presented. It was shown that the alloyed powder used in the current study presents more thermodynamic stability than previously reported ball-milled powders. Based on hardness values, it was shown that mechanical strength is expected to be retained at higher processing temperatures. Lastly, a 2-dimensional heat transfer model was used to understand heat flow through the powder compacts.

Hydration Resistance of Al/AlN Bonded Corundum Based Multiphase Material

2008 ◽  
Vol 368-372 ◽  
pp. 1133-1136
Author(s):  
Bin Xiang Fang ◽  
Bo Quan Zhu ◽  
Wen Jie Zhang ◽  
Xue Dong Li ◽  
Zheng Yun Fan
Keyword(s):  
Raw Materials ◽  
Xrd Analysis ◽  
Metallic Aluminum ◽  
Hydration Mechanism ◽  
Multiphase Material ◽  
Prepared Material ◽  
Hydration Resistance ◽  
Xrd Patterns ◽  
High Level

The Al/AlN bonded corundum based multiphase material was prepared by raw materials of fused alumina and metallic aluminum powder by in situ reaction at 1100°C for 3h in N2 . The XRD analysis showed that the mineral phases of prepared material are corundum, metallic aluminum and AlN respectively. The SEM investigation revealed that both tetragonal whiskers and hexagon powders of AlN were formed. The results of hydration tests indicated that the rate of weight gain and pulverization of the material were negligible and the ratio of residual crushing strength was kept at a high level. The XRD patterns of samples after hydration tests identified that the AlN phase still remained although a small amount of AlOOH and Al(OH)3 was formed due to the hydration of AlN. It is believed that the limited hydration of AlN should be contributed to the dissolution of O element to AlN. The hydration mechanism of AlN was discussed.

Synthesis and Characterization of Ti2AlC and Ti2AlN MAX Phase Coatings Manufactured in an Industrial-Size Coater

2010 ◽  
Vol 89-91 ◽  
pp. 208-213 ◽  
Author(s):  
W. Garkas ◽  
Christoph Leyens ◽  
A. Flores-Renteria
Keyword(s):  
Magnetron Sputtering ◽  
Annealing Treatment ◽  
Xrd Analysis ◽  
Max Phase ◽  
Synthesis And Characterization ◽  
Dc Magnetron Sputtering ◽  
Max Phases ◽  
Coating Deposition

Due to a nanolaminate structure, MAX phases are materials with an interesting set of properties. The present paper is focussed on the synthesis and characterization of Ti2AlC and Ti2AlN MAX phase coatings. They were deposited by dc magnetron sputtering from single elemental Ti, Al, and C targets (Ti-Al-C system); in addition to Ti and Al, nitrogen was used for the Ti-Al-N system. XRD analysis revealed the growth of cubic Ti3AlC and Ti3AlN perovskite phases in the coatings deposited at 540°C. After coating deposition an annealing treatment at 800, 1000 and 1200°C was carried out. The results indicate that annealing for 1 h in vacuum at 800°C enhances crystallization of the Ti2AlN and Ti2AlC MAX phases. It was also observed that annealing at temperatures higher than 1000°C enhances the decomposition of both phases, Ti2AlC and Ti2AlN, and gives rise to the formation of the carbide and nitride phases TiCx and TiNx, respectively.

scholarly journals Effect of processing parameters on microstructural properties of lead magnesium niobates

2017 ◽  
Vol 73 (6) ◽  
pp. 1095-1104 ◽  
Author(s):  
Ashok Bhakar ◽  
Adityanarayan H. Pandey ◽  
M. N. Singh ◽  
Anuj Upadhyay ◽  
A. K. Sinha ◽  
...  
Keyword(s):  
Rietveld Refinement ◽  
Rhombohedral Phase ◽  
Average Crystallite Size ◽  
Cubic Phase ◽  
Gaussian Component ◽  
Processing Temperature ◽  
Microstructural Properties ◽  
Weight Percentage ◽  
Lead Magnesium ◽  
Xrd Patterns

The synchrotron powder X-ray diffraction (XRD) and subsequent detailed Rietveld analysis of lead magnesium niobate (PMN) samples were performed to study the microstructural properties of polar nanoregions (PNRs) of the R3m phase. PMN samples were synthesized under different sample processing conditions. The line profile broadening analysis of room-temperature synchrotron powder XRD patterns was performed using the multi-phase Rietveld refinement method for isotropic microstructural evaluation of different PMN samples. The two phases of perovskite PMN considered in the Rietveld refinement approach for satisfactorily fitting the XRD patterns are the paraelectric cubic phase (Pm\overline 3m) and the local rhombohedral phase (R3m) which corresponds to the PNRs. It is observed that the contributions of the Gaussian component of size broadening of the polar rhombohedral phase (R3m) and the Lorentzian component of strain broadening of the paraelectric cubic phase (Pm\overline 3m) are apposite for satisfactory Rietveld refinement of the synchrotron XRD data for all PMN samples. The volume-average crystallite size of PNRs (R3m phase) is almost invariant (approximately 12 nm) with increasing processing temperature while their weight percentage increases. The values of the apparent microstrain in the paraelectric cubic phase (Pm\overline 3m) are larger for hot-pressed samples.

Structure identification of Nd1-xYbxFeO3 (x = 0.01, 0.05 and 0.10) using Rietveld refinement method

2021 ◽  
Author(s):  
Eko Hadi Sujiono ◽  
Vicran Zharvan ◽  
Sultra Ade Poetra ◽  
Muthmainnah Muchtar ◽  
Abdi Manab Idris ◽  
...  
Keyword(s):  
Rietveld Refinement ◽  
Structure Identification ◽  
Refinement Method

scholarly journals Microstructure and properties of nano-laminated Y3Si2C2 ceramics fabricated via in situ reaction by spark plasma sintering

2021 ◽  
Vol 10 (3) ◽  
pp. 578-586
Author(s):  
Lin-Kun Shi ◽  
Xiaobing Zhou ◽  
Jian-Qing Dai ◽  
Ke Chen ◽  
Zhengren Huang ◽  
...  
Keyword(s):  
Spark Plasma Sintering ◽  
Atomic Scale ◽  
Max Phase ◽  
X Ray Diffraction ◽  
Selected Area Electron Diffraction ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma ◽  
Diffraction Patterns

AbstractA nano-laminated Y3Si2C2 ceramic material was successfully synthesized via an in situ reaction between YH2 and SiC using spark plasma sintering technology. A MAX phase-like ternary layered structure of Y3Si2C2 was observed at the atomic-scale by high resolution transmission electron microscopy. The lattice parameters calculated from both X-ray diffraction and selected area electron diffraction patterns are in good agreement with the reported theoretical results. The nano-laminated fracture of kink boundaries, delamination, and slipping were observed at the tip of the Vickers indents. The elastic modulus and Vickers hardness of Y3Si2C2 ceramics (with 5.5 wt% Y2O3) sintered at 1500 °C were 156 and 6.4 GPa, respectively. The corresponding values of thermal and electrical conductivity were 13.7 W·m-1·K-1 and 6.3×105 S·m-1, respectively.

Zirconium phase transformations observed by “in-situ” XRD analysis

Vacuum ◽  
2012 ◽  
Vol 86 (6) ◽  
pp. 785-788 ◽  
Author(s):  
Jan Riha ◽  
Pavol Sutta ◽  
Andrej Vincze ◽  
Rostislav Medlin
Keyword(s):  
Phase Transformations ◽  
Xrd Analysis ◽  
In Situ Xrd

Phase evolution during laser In-Situ carbide coating

2005 ◽  
Vol 36 (13) ◽  
pp. 797-803 ◽  
Author(s):  
Anshul Singh ◽  
Narendra B. Dahotre
Keyword(s):  
Phase Evolution ◽  
Carbide Coating
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