Microstructure and Mechanical Properties of AISI 8620 Steel Processed by ECAP

2014 ◽  
Vol 1611 ◽  
pp. 89-94
Author(s):  
Diana M. Marulanda ◽  
Jair G. Cortés ◽  
Marco A. Pérez ◽  
Gabriel García
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Equivalent Strain ◽  
Sem Analysis ◽  
Structure Evolution ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angular Pressing ◽  
Before And After

ABSTRACTThe aim of this work is to process by equal channel angular pressing (ECAP) a low carbon – triple-alloyed steel containing 0.2% C, 0.5% Cr, 0.6% Ni, 0.2% Mo and 0.8 Mo. The process is performed at room temperature for up to four passes using route Bc with an equivalent strain of ∼0.6 after a single pass. Structure evolution before and after deformation is studied using scanning electron microscopy (SEM) and x-ray diffraction (XRD) and mechanical properties are assessed by microhardness and tensile testing. A significant improvement of the mechanical properties is found with increasing number of ECAP passes. Micro-hardness increases from 216 HV for the initial sample to 302 HV after four passes and tensile strength increases to 1200 MPa compared with 430 MPa prior to ECAP. X-ray diffraction and SEM analysis show changes in the original ferritic-perlitic structure through ferrite grain refinement and the deformation of perlite. This nickel-chromium-molybdenum alloy is used in manufacturing as gear material, and when it is hardened and formed through carburizing or boronizing it can be used to make hard-wearing machine parts. However, the ECAP process has not been used to harden this steel and to change its structure to obtain better mechanical performance.

scholarly journals Functional Bionanocomposite Fibers of Chitosan Filled with Cellulose Nanofibers Obtained by Gel Spinning

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1563
Author(s):  
Sofia Marquez-Bravo ◽  
Ingo Doench ◽  
Pamela Molina ◽  
Flor Estefany Bentley ◽  
Arnaud Kamdem Tamo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Cellulose Nanofibers ◽  
Microstructural Characterization ◽  
Fiber Formation ◽  
Fiber Direction ◽  
Composite Fibers ◽  
X Ray Diffraction ◽  
Gel Spinning ◽  
X Ray

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m−3. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties.

Preparation and Characterization of PVA-Collagen Composite Fibers

2011 ◽  
Vol 236-238 ◽  
pp. 83-86 ◽  
Author(s):  
Xian Hui Sun
Keyword(s):  
Mechanical Properties ◽  
Sem Analysis ◽  
Composite Fibers ◽  
X Ray Diffraction ◽  
Natural Structure ◽  
Uniform Size ◽  
X Ray ◽  
Rheology Property ◽  
Crystallization Degree

The collagen was blended with polyvinyl alcohol (PVA) with the maximum maintenance of the natural structure as precondition. The apparent viscosity and rheology property of PVA-collagen blended solution were studied. the mechanical properties of the blend membrane formed from PVA-collagen blended solution were also determined. The PVA-collagen blended solution was wet spinned with the sodium sulfate as coagulant to prepare PVA-collagen composite fibers. SEM analysis and X-ray diffraction analysis of the PVA-collagen composite fibers were studied. The results indicated that, blended with PVA, the spinning property and mechanical properties of collagen were improved. The figure of the aim fiber transect structure was similar as the kidney, and it had a uniform size. The crystallization degree of the fiber was 55.7%, and it was increased with the increase of the hot extending temperature and the extending ratio.

Research on Solid Wastes of Gangue, Slag, Fly Ash Used as Cement Composite Mixing Materials

2011 ◽  
Vol 415-417 ◽  
pp. 1486-1489
Author(s):  
Jian Guo Liao ◽  
Qian Ma ◽  
Yi Shun Zhang ◽  
Zhi Yang Song ◽  
Kai Hang Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Composite ◽  
Sem Analysis ◽  
Solid Wastes ◽  
X Ray Diffraction ◽  
Compact Structure ◽  
X Ray ◽  
Before And After ◽  
Mixed Material ◽  
Cement Strength

The purpose of this study is to bring the fly ash, coal gangue and slag industrial solid wastes which contain the chemical composition for activation treatment, used as activated composite cement mixing materials, through strength test shows that the compound mixing materials impermeability activation treatment can obviously increase the cement strength. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) analysis results showed that the crystal structure of the mixed material calcined before and after have apparent change. There are lesss hydration products with compact structure of cement hydration 3d. The early strength of aiding composite mixing materials cement improved greatly.

Influence of Temperature of Accumulative Roll Bonding on the Microstructure and Mechanical Properties of AA5251 Aluminum Alloy

2014 ◽  
Vol 59 (1) ◽  
pp. 127-131 ◽  
Author(s):  
J. Bogucka
Keyword(s):  
Mechanical Properties ◽  
Ambient Temperature ◽  
Accumulative Roll Bonding ◽  
Bonding Temperature ◽  
Tensile Tests ◽  
Structure Evolution ◽  
X Ray Diffraction ◽  
Roll Bonding ◽  
X Ray ◽  
Microstructure And Mechanical Properties

Abstract The influence of bonding temperature on microstructure and mechanical properties of AA5251 alloy sheets have been analyzed in the paper. The alloy was deformed with the method of accumulative roll bonding (ARB) in various temperature conditions i.e. at ambient temperature up to 5th cycle (ε = 4.0) and using pre-heating of sheet packs at 200°C and 300°C up to 10 cycles (ε = 8.0). The deformed material was subjected to structural observations using TEM, measurements of crystallographic texture with the technique of X-ray diffraction and tensile tests. It was established that the temperature of roll-bonding had a significant effect on the structure evolution and the observed changes of mechanical properties. High refinement of microstructure and optimum mechanical properties were obtained for the material processed at lower temperatures, i.e. at ambient temperature and pre-heating at 200°C. Recovery structure processes occurring during deformation were observed in the alloy bonded with pre-heating at 300°C and therefore mechanical properties were lower than for the alloy bonded at lower temperatures.

Investigation on the nucleation mechanism of deformation-induced martensite in an austenitic stainless steel under severe plastic deformation

2007 ◽  
Vol 22 (3) ◽  
pp. 724-729 ◽  
Author(s):  
C.X. Huang ◽  
G. Yang ◽  
Y.L. Gao ◽  
S.D. Wu ◽  
S.X. Li
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Nucleation Mechanism ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
Transformation Mechanism ◽  
X Ray ◽  
Angular Pressing ◽  
Transmission Electron

The nucleation mechanism of deformation-induced martensite was investigated by x-ray diffraction and transmission electron microscope in an ultra-low carbon austenitic stainless steel deformed by equal channel angular pressing at room temperature. It was found that two types of martensite transformation mechanism, stress-assisted and strain-induced, occurred via the sequences of γ (fcc) → ɛ (hcp) → α′ (bcc) and/or γ → α′. In both cases, the crystallographic relationships among γ, ɛ, and α′ followed the Kurdjumov-Sachs orientation relationships: {111}γ //{0001}ɛ //{011}α′ and 〈110〉γ//〈1120〉ɛ//〈111〉α′.

scholarly journals PEEK filament characteristics before and after extrusion within fused filament fabrication process

2022 ◽  
Author(s):  
Cleiton André Comelli ◽  
Richard Davies ◽  
HenkJan van der Pol ◽  
Oana Ghita
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Extrusion Process ◽  
X Ray Diffraction ◽  
Fused Filament Fabrication ◽  
Scanning Calorimetry ◽  
Fast Scanning Calorimetry ◽  
Transmission Electron ◽  
Before And After ◽  
History Of

AbstractThe heating and extrusion process in fused filament fabrication (FFF) is significantly shorter than the conventional extrusion process where longer heating times and significant pressure are applied. For this reason, it is important to understand whether the crystal history of the feedstock is fully erased through the FFF process and whether the FFF process can be tailored further by engineering the crystallization of the feedstock filaments. In this context, a methodology for evaluating the influence of morphology and mechanical properties on different feedstock and extruded filaments is proposed. Filaments with three different PEEK 450G crystalline structures (standard crystallinity, drawn filament and amorphous filament) were selected and evaluated, before and after free extrusion. The resulting morphology, crystallinity and mechanical properties of the extruded filaments were compared against the feedstock properties. X-ray diffraction (XRD), transmission electron microscopy (TEM), differential and fast scanning calorimetry (DSC/FDSC) and tensile test were the techniques used to evaluate the materials. The results showed clear differences in the properties of the feedstock materials, while the analysis of the extruded filaments points to a homogenization of the resulting material producing mostly similar mechanical properties. However, the use of the drawn filament highlighted a statistically significant improvement in crystallinity and mechanical performance, especially in strain values. This conclusion suggests the innovative possibility of improving the quality of manufactured parts by tailoring the microstructure of the feedstock material used in the FFF process. Graphical abstract

Effect of Sintering Aid on Microstructure and Mechanical Properties of TiB2/TiN Tool Materials

2011 ◽  
Vol 287-290 ◽  
pp. 1933-1937 ◽  
Author(s):  
Mei Lin Gu ◽  
Jian Hua Zhang ◽  
Zhi Wei
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Sem Analysis ◽  
Eutectic Phase ◽  
X Ray Diffraction ◽  
Sintering Aid ◽  
X Ray ◽  
Tool Materials ◽  
Abnormal Growth ◽  
Microstructure And Mechanical Properties

TiB2/TiN composites with various content of Ni and Mo as sintering aid were hot-pressed at 1530°C. Effect of the content of sintering aid on microstructure and mechanical properties is investigated. Experimental results show that the fracture toughness of the composites increases consistently with an increase in the sintering aid content, however, the flexural strength gets to the maximum when the content of sintering aid is 10vol%. A new eutectic phase of MoNi can be found in the composites by X-ray diffraction (XRD) when the amount of sintering aid is over 7vol%. Scan electron microscope (SEM) analysis shows that the density of the composites increases consistently with the increasing of the sintering aid. But the abnormal-growth grains can be found and deteriorates the flexural strength in the composite No.4 because of the excessive sintering aid.

Effects Studying of Annealing to Mechanical Properties Carbon-Doped Ti-O Films Synthesized Using CO2 Gas

2017 ◽  
Vol 727 ◽  
pp. 915-922
Author(s):  
Hong Wu Liu ◽  
Yong Yao Su ◽  
Xiao Yu Huang ◽  
Jian Lu Xue ◽  
Feng Wen
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Annealing Temperature ◽  
Mechanical Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Doped ◽  
Structure And Morphology ◽  
Xrd Studies ◽  
Electronic Microscope

Carbon-doped Ti-O films were deposited on steel and silicon wafer by DC reaction magnetron sputtering (R-MS) using CO2 as carbon and oxygen source. A series of films were prepared by means of changing the flow of CO2 or O2. The effects of annealing temperature ranging from 300 to 650°C on the properties of Ti-O films under vacuum were studied. X-ray diffraction (XRD) and field emission scanning electronic microscope (FESEM) were employed to analyze and observe structure and morphology of pre-or after-annealed Ti-O films. nanoindentation was used to measure nanohardness and modulus, and recovery was also calculated by the curves of load-displacement. Roughness and thickness were estimated by surface profiler. The XRD studies revealed that the doping of carbon was beneficial to the crystallization of the films. The results showed that the particle size of Ti-O films increased with the increase of annealing temperature, as-annealed carbon-doped Ti-O films have fair mechanical performance.

scholarly journals Potential Peat Clay for Minerals Source Utilized as Adsorbent and Catalyst

2019 ◽  
Vol 280 ◽  
pp. 04003
Author(s):  
Agus Mirwan ◽  
Meilana Dharma Putra ◽  
Riani Ayu Lestari
Keyword(s):  
Xrd Analysis ◽  
Sem Analysis ◽  
X Ray Diffraction ◽  
Huge Amount ◽  
Calcination Process ◽  
X Ray ◽  
Potential Source ◽  
Before And After ◽  
Flake Structure

The existence of peat clay is scattered in many parts of the world with the huge amount. The high compound of minerals in the peat clay can be potentially used as adsorbent and catalyst. This research aims to study the composition of peat clay and functional group of the compound in the peat clay. The characterization of x-ray fluorescence (XRF), fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and scanning electron microscope-energy dispersive x-ray (SEM- EDX) were assigned to compare the sample before and after calcination process at 700 oC 120 min. FTIR analysis showed the presence of quartz, kaolinite, hematite, illite in peat clay. The results of XRF analysis showed that chemical composition of peat clay was dominantly in the form of silica oxide (18%), aluminum oxide (7%), and iron oxide (15%). The amount of compounds was observed to increase to be 32%, 18% and 11%, respectively after calcinations. XRD analysis confirmed the presence of this mineral in the peat clay. SEM analysis showed flake structure of peat clay with EDX which indicated composition of the dominant element namely the presence of Al, Si, and Fe before and after calcination. This high amount of minerals in peat clay led to potential source to be utilized as adsorbent for removing the pollutant or as and catalyst for chemical process.

scholarly journals Electrophoretic Deposition of 45S5 Bioglass® Coatings on the Ti6Al4V Prosthetic Alloy with Improved Mechanical Properties

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1192
Author(s):  
Imen Azzouz ◽  
Joël Faure ◽  
Kaouther Khlifi ◽  
Ahmed Cheikh Larbi ◽  
Hicham Benhayoune
Keyword(s):  
Mechanical Properties ◽  
Electrophoretic Deposition ◽  
Scratch Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Suspension ◽  
Test Study ◽  
Before And After ◽  
Titanium Alloy Ti6al4v ◽  
45S5 Bioglass

In this paper, 45S5 Bioglass® coatings were elaborated by electrophoretic deposition (EPD) on the titanium alloy Ti6Al4V. An adequate grinding protocol was developed to obtain a stable suspension of submicrometric particles in isopropanol. The voltage and the deposition time of EPD were optimized. An optimal voltage of 30 V and two deposition times (30 and 90 s) were chosen to obtain two different coatings with thicknesses of 21 and 85 µm, respectively. The as-deposited coatings were thermally treated following a two-step protocol: one hour at 120 °C followed by one hour at 450 °C. The surface morphology and the chemical analysis of the 45S5 Bioglass® coatings were assessed, before and after heat treatment, by scanning electron microscopy associated to X-ray microanalysis (SEM-EDXS). Their structural analysis was performed by X-ray diffraction (XRD). A scratch test study was developed for mechanical properties analysis. The obtained results revealed that the obtained coatings were homogeneous, weakly crystallized with an important compactness. An increase in the critical load LC associated with the cohesive limit of the film (from Lc = 3.39 N to Lc = 5.18 N) was observed when the coating thickness was decreased from 85 to 21 µm. After the thermal treatment, the chemical composition of the coatings was not altered, and their mechanical properties were improved.

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