scholarly journals EBSD analysis of graphitized steel microstructure after compression deformation at room temperature

2021 ◽  
Vol 64 (3) ◽  
pp. 230-236
Author(s):  
Y. Zhang
Keyword(s):  
Room Temperature ◽  
Large Deformations ◽  
Testing Machine ◽  
Taylor Factor ◽  
Deformation Degree ◽  
Cold Forming ◽  
Compression Deformation ◽  
Good Ability ◽  
The Matrix ◽  
Graphite Inclusions

 The graphitized steel has attracted considerable attention due to its excellent cutability and good properties at cold forming. Compression deformation at room temperature of graphitized steel (0.43 % C) with a ferrite-graphite microstructure was performed on a universal testing machine. Microstructures of deformed samples were studied using the analysis technique of Electron Back-Scattered Diffraction (EBSD). The evolution of microstructure morphology, texture, distribution of Kernel Average Misorintations (KAM) and the Taylor factor in the zone of large deformations of deformed samples with different degrees of deformation is discussed. The results show that the studied steel has a good ability to compression deformation. During compression deformation, with an increase in deformation degree the deformation morphology of the ferrite grain and graphite inclusions gradually stretch in the direction perpendicular to the compression axis and they are represented as fibrous forms. The orientation of ferrite grains in the matrix is gradually obvious, and the orientation of ferrite grains around graphite inclusions is not obvious, that is, the number of grains oriented to <100>, <111> in the matrix is much greater than around graphite inclusion. In addition, KAM and the Taylor factor in the large deformations region of compression samples show that the deformation degree of ferrite grains around graphite inclusions is less than that of ferrite grains in the matrix. The reason for this is that the soft graphite inclusions can reduce the degree of dislocation pile-up.

A Trial of FGM Bearings with Solid Lubricant

2009 ◽  
Vol 631-632 ◽  
pp. 465-470
Author(s):  
Takashi Hashimoto ◽  
Hitoshi Kohri ◽  
Atsushi Yumoto ◽  
Ichiro Shiota
Keyword(s):  
Friction Surface ◽  
Room Temperature ◽  
Electroless Deposition ◽  
Solid Lubricant ◽  
Volume Fraction ◽  
Testing Machine ◽  
High Load ◽  
Lubricant Oil ◽  
The Matrix ◽  
Composite Bearing

It is difficult to use an ordinary plain bearing under a high load or at a high friction speed because lubricant oil is pushed out from the friction surface or deterioration of the lubricant oil is caused by heat of friction. A solid lubricant, MoS2, is promising in such condition. When the lubricant is dispersed in a matrix, the solid lubricant is always supplied from the matrix. Such a composite bearing needs a back metal to maintain its shape. The heat of friction may cause a crack between the bearing and the back metal due to thermal stress. A bearing with low coefficient of friction is necessary to decrease the heat of friction, and an FGM structure is also promising to decrease the stress. The aim of this experiment is to fabricate and to examine friction properties of the composites. Cu was plated on the lubricant particles by electroless deposition. The lubricant volume fraction (hereafter Vf) was up to Vf 30 %. The Cu plated lubricant particles were hot-pressed to form a composite at 873 K under 30 MPa in a vacuum. Friction properties of the composites were determined by using a ball-on-disk type testing machine. The test was performed in the air without oil at room temperature. The solid lubricant in the composites was effective to decrease the coefficients of friction under a high load when the Vf was higher than 20 %.

scholarly journals Synthesis and Characterization and Properties Comparison of Epoxy Filled Filler Millet (Ragi) Filler and Treated Sacharun offinarum (Sugar Cane) Fiber Reinforced Composites

2015 ◽  
Vol 51 ◽  
pp. 41-46 ◽  
Author(s):  
U. Mahaboob Basha ◽  
D. Mohana Krishnudu ◽  
P. Hussain ◽  
K. Manohar Reddy ◽  
N. Karthikeyan ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hybrid Composites ◽  
Thermo Gravimetric Analysis ◽  
Testing Machine ◽  
Gravimetric Analysis ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Universal Testing ◽  
The Matrix

In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, filler millet(Ragi) filler is chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and filler millet (Ragi) filler is synthesised by mechanical shear mixer, then kept in a Ultra sonic Solicitor for better dispersion of filler millet (Ragi) filler in the matrix. Different weights of modified filler millet(Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.Mechanical properties like Flexural strength, Tensile strength and impact strength of the micro hybrid composite are studied by UTM (Universal Testing Machine). Thermal properties of micro hybrid composites are studied using Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

ALCHEMI of B2-Ordered Fe50Al45Me5 alloys

1996 ◽  
Vol 54 ◽  
pp. 548-549
Author(s):  
Ian M. Anderson
Keyword(s):  
Room Temperature ◽  
Iron Aluminide ◽  
Low Density ◽  
Intermetallic Alloys ◽  
Practical Applications ◽  
Alloying Additions ◽  
Site Distribution ◽  
Good Corrosion Resistance ◽  
Room Temperature Ductility ◽  
The Matrix

B2-ordered iron aluminide intermetallic alloys exhibit a combination of attractive properties such as low density and good corrosion resistance. However, the practical applications of these alloys are limited by their poor fracture toughness and low room temperature ductility. One current strategy for overcoming these undesirable properties is to attempt to modify the basic chemistry of the materials with alloying additions. These changes in the chemistry of the material cannot be fully understood without a knowledge of the site-distribution of the alloying elements. In this paper, the site-distributions of a series of 3d-transition metal alloying additions in B2-ordered iron aluminides are studied with ALCHEMI.A series of seven alloys of stoichiometry Fe50AL45Me5, with Me = {Ti, V, Cr, Mn, Co, Ni, Cu}, were prepared with identical heating cycles. Microalloying additions of 0.2% B and 0.1% Zr were also incorporated to strengthen the grain boundaries, but these alloying additions have little influence on the matrix chemistry and are incidental to this study.

The butterfly martensite nucleation in an iron and nickel alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 906-907
Author(s):  
Q.Z. Chen ◽  
X.F. Wu ◽  
T. Ko
Keyword(s):  
Nickel Alloy ◽  
Ethyl Alcohol ◽  
Dislocation Structure ◽  
Martensite Transformation ◽  
Room Temperature ◽  
The Matrix

Some butterfly martensite nuclei were observed in an Fe-27.6Ni-0.89V-0.05C alloy. The alloy was austenitized at 1200°C for 1 hour. Some samples were aged at 850° C for 40 minutes and quenched in 10% brine at room temperature. All the samples were cooled in ethyl alcohol for martensite transformation.A nucleus in an unaged specimen is shown in Fig.1. The nucleus has certain contrast different from the matrix and is shaped like one wing of a butter fly martensite. The SADP of the circled region is measured to be: da=dh, and approximate to dγ(111) and dm(110) with ∠AOB = 55° . It is similar to [011]f.c.c and b patterns in the anglez ∠AOB and the ratio ra/rb, respectively. The SADP shows that the structure of the nucleus is between f.c.c and b.c.c. The dislocation structure within the nucleus is shown in Fig.2. Their Burgers vectors and line directions are also given in it. There are many long dislocations near it without dislocations piled up as shown in Fig.3.Long dislocations are closed at one end as an envelope.

Lead inclusions in aluminium

1989 ◽  
Vol 157 ◽  
Author(s):  
E. Johnson ◽  
L. Gråbaek ◽  
J. Bohr ◽  
A. Johansen ◽  
L. Sarholt-Kristensen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Room Temperature ◽  
Noble Gas ◽  
Melting Transition ◽  
X Ray Diffraction ◽  
Free Surfaces ◽  
The Matrix ◽  
Mean Size ◽  
The Mean ◽  
Spontaneous Phase

ABSTRACTIon implantation at room temperature of lead into aluminium leads to spontaneous phase separation and formation of lead precipitates growing topotactically with the matrix. Unlike the highly pressurised (∼ 1–5 GPa) solid inclusions formed after noble gas implantations, the pressure in the lead precipitates is found to be less than 0.12 GPa.Recently we have observed the intriguing result that the lead inclusions in aluminium exhibit both superheating and supercooling [1]. In this paper we review and elaborate on these results. Small implantation-induced lead precipitates embedded in an aluminium matrix were studied by X-ray diffraction. The (111) Bragg peak originating from the lead crystals was followed during several temperature cycles, from room temperature to 678 K. The melting temperature for bulk lead is 601 K. In the first heating cycle we found a superheating of the lead precipitates of 67 K before melting occurred. During subsequent cooling a supercooling of 21 K below the solidification point of bulk lead was observed. In the subsequent heating cycles this hysteresis at the melting transition was reproducible. The full width of the hysteresis loop slowly decreased to 62 K, while the mean size of the inclusions gradually increased from 14.5 nm to 27 nm. The phenomena of superheating and supercooling are thus most pronounced for the small crystallites. The persistence of the hysteresis loop over successive heating cycles demonstrate that its cause is intrinsic in nature, and it is believed that the superheating originates from the lack of free surfaces of the lead inclusions.

The Effects of Hydrothermal Ageing on the Crushing Behavior of Glass/Epoxy Composite Pipes

2015 ◽  
Vol 819 ◽  
pp. 411-416
Author(s):  
S.N. Fitriah ◽  
M.S. Abdul Majid ◽  
R. Daud ◽  
M. Afendi ◽  
Z.S. Nazirah
Keyword(s):  
Composite Laminates ◽  
Testing Machine ◽  
Hydrothermal Condition ◽  
Compression Tests ◽  
Universal Testing ◽  
Failure Region ◽  
The Matrix ◽  
Glass Fibre Reinforced ◽  
Crushing Behavior ◽  
Composite Pipes

The paper discusses the crushing behavior of glass fibre reinforced epoxy (GRE) pipes under hydrothermal ageing condition. This study determines the behavior of the GRE pipes when subjected to different ageing periods and temperatures. Hydrothermal ageing has been found to cause degradation between resin and fibre interface thus causing the reduction in the strength of composite laminates. The pipes were subjected to hydrothermal condition to simulate and precipitate ageing by immersing the pipe samples in water at 80°C for 250, 500, and 1000 hours. Compression tests were carried out using Universal Testing Machine (UTM) for virgin condition and aged samples in accordance with ASTM D695 standard. The maximum force at the initial failure region is observed for each of the conditioned pipes. The results show that the strength of the matrix systems was considerably degraded due to the plasticization of the matrix system.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

scholarly journals PENGARUH PENINGKATAN DERAJAT DEFORMASI CANAI HANGAT TERHADAP KARAKTERISTIK DEFORMATION BAND PADUAN Cu-Zn 70/30

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Eka Febriyanti ◽  
Dedi Priadi ◽  
Rini Riastuti
Keyword(s):  
Deformation Band ◽  
Cold Working ◽  
Testing Machine ◽  
Deformation Bands ◽  
Double Pass ◽  
Deformation Degree ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
Hot Rolled ◽  
Zn Alloy

Cu-Zn 70/30 alloy has properties that is relatively soft, ductile, and easy to perform by cold working. However, cold working has the disadvantage that require equipment which has higher loading capacity to generate strength and higher density thus increasing of machining cost. In addition, strain hardening phenomenon due to cold working process resulted in decreasing of ductility material. Therefore, it is necessary alternative fabrication processes to optimize the mechanical properties of Cu-Zn alloy 70/30 that with the TMCP method. TMCP is metal forming material by providing large and controlled plastic strain to the material. TMCP using the deformation percentage variation that 32.25%, 35.48%, and 38.7% from hot rolled research at 500°C temperature in double pass reversible which performed on Cu-Zn 70/30 plate. By tensile testing using universal testing machine can be seen that the Cu-Zn 70/30 alloy on 32.25% degree of deformation, both of UTS and YS respectively are 505 MPa and 460 MPa. Whereas from examination of thickness and density deformation bands by FE-SEM shows denser and thicker deformation band proportional with increasing of deformation degree.Moreover, the values of tensile strength at the edge of the area and the center is directly proportional to the density and thickness of the deformation band.AbstrakPaduan Cu-Zn 70/30 memiliki sifat yang relatif lunak, ulet, dan mudah dilakukan pengerjaan dingin. Namun, pengerjaan dingin memiliki kekurangan yaitu membutuhkan peralatan yang memiliki kapasitas pembebanan tinggi untuk menghasilkan kekuatan dan kepadatan tinggi sehingga meningkatkan biaya permesinan. Selain itu, fenomena pengerasan regang akibat proses pengerjaan dingin menghasilkan penurunan keuletan material. Oleh karena itu, diperlukan alternatif proses fabrikasi untuk mengoptimalkan sifat mekanik paduan Cu-Zn 70/30 salah satunya dengan metode TMCP. TMCP merupakan suatu proses perubahan bentuk suatu material dengan cara memberikan regangan plastis yang besar dan terkontrol terhadap material. TMCP dengan menggunakan variasi persentase deformasi sebanyak 32,25%, 35,48%, dan 38,70% dari penelitian canai hangat di suhu 500oC secara double pass reversible dilakukan pada pelat paduan Cu-Zn 70/30. Dengan melakukan pengujian tarik menggunakan mesin uji tarik universal testing machine dapat dilihat bahwa pada material paduan Cu-Zn 70/30 pada derajat deformasi 32,25% menghasilkan nilai UTS dan YS masing-masing sebesar 505 MPa dan 460 MPa. Sedangkan dari hasil pengamatan ketebalan dan kerapatan deformation band menggunakan FE-SEM menunjukkan deformation band yang lebih rapat dan lebih tebal sebanding dengan semakin meningkatnya derajat deformasi. Selain itu, nilai kekuatan tarik pada daerah tepi dan tengah berbanding lurus dengan kerapatan dan ketebalan deformation band.Keywords: 70/30 Cu-Zn alloy, warm rolled, deformation degree, deformation bands

scholarly journals TEMPERATURE DEPENDENCE OF CONDUCTIVITYOF UREASE DOPED POLYPYRROLE MATERIAL

2021 ◽  
Vol 9 (6) ◽  
pp. 85-90
Author(s):  
Munish Pandey ◽  
Richa Badlani
Keyword(s):  
Infrared Spectroscopy ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Chemical Oxidation ◽  
Oxidation Method ◽  
Temperature Range ◽  
The Matrix

In polymerization of was carried out in the presence of to synthesize – composites by chemical oxidation method. The / have been synthesized with various compositions (10, 15, 20, 25 and 30 ) of in in aquas medium at room temperature. The – composites were characterized by infrared spectroscopy (IR). The d.c. conductivity was studied in the temperature range from 40–100°C. The dimensions of in the matrix have a greater influence on the observed conductivity values.

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