Influence of Asymmetric Rolling on the Deformation Textures, Grain Size and Mechanical Properties of B4C/Al Composite

2016 ◽  
Vol 851 ◽  
pp. 196-200
Author(s):  
Bing Feng Li ◽  
Qiu Lin Li ◽  
Wei Liu ◽  
Zhen Hong Wang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Volume Fraction ◽  
Small Diameter ◽  
Diameter Ratio ◽  
Asymmetric Rolling ◽  
Al Composite ◽  
Average Grain Size ◽  
Cold Rolling And Annealing ◽  
Deformation Textures

B4C/Al composite was a promising neutron absorb material. In this work, B4C/Al composite sheets were asymmetrically rolled and annealed. The asymmetric (ASR) condition was introduced by applying mismatched roll diameters with diameter ratios of 1.1, 1.2 and 1.3, respectively., while the symmetric rolling (SR) was used as the control experiment. Mechanical properties and microstructures of the composite were tested after cold rolling and annealing. Results showed that: ASR with small diameter ratio decreased the texture volume fraction in the B4C/Al composite, but when diameter ratio of ASR reached 1.3 new slip systems were actuated and the texture volume fraction started to increase. The average grain size of the aluminium matrix was smaller after ASR, and it decreased with the increasing diameter ratio. The hardness of B4C/Al composite after ASR was about 40% higher than the one rolled by symmetric rolling, proved that ASR is a promising way to enhance the properties of B4C/Al composite.

scholarly journals Enhanced Mechanical Properties of Mg-6Sn-3Al-1Zn Alloy with Bimodal Grain Size Disturbed in the Microstructure Uniformly through Changing the Rolling Temperature

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Fuan Wei ◽  
Jinhui Wang ◽  
Ping Li ◽  
Bo Shi
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Yield Strength ◽  
Volume Fraction ◽  
Rolling Temperature ◽  
Average Grain Size ◽  
Small Grains ◽  
Mg2sn Phase ◽  
Average Size ◽  
Bimodal Grain Size

The mechanical properties of Mg-6Sn-3Al-1Zn alloy were enhanced with bimodal grain size disturbed in the microstructure uniformly; the Mg-6Sn-3Al-1Zn alloys were rolled with 60% thickness reduction at different rolling temperatures. The results have shown that the Mg-6Sn-3Al-1Zn alloys are composed of Mg2Sn phase and α-Mg matrix phase. When the rolling temperature was less than or equal to 400°C, with the rolling temperature increasing, the average size and volume fraction of Mg2Sn phase and the average grain size of small grains remained unchanged, the average grain size of large grains decreased, the volume fraction of small grains increased, and the yield strength of the alloy increased. When the rolling temperature reached 450°C, the average size and volume fraction of Mg2Sn phase and the average grain size of large grains increased, and the volume fraction of small grains and the yield strength of the alloy decreased. The elongation increased with the rolling temperature increasing, but the change trend of hardness was just opposite. When the alloy was rolled at 400°C, the average sizes of small grains, large grains, and Mg2Sn phases were 3.66 μm, 9.24 μm, and 19.5 μm, respectively. The volume fractions of small grains, large grains, and Mg2Sn phases were 18.6%, 77.6%, and 3.8%, respectively. And the tensile properties reached the optimum; for example, the tensile strength, yield strength, elongation, and Vickers hardness were 361 MPa, 289.5 MPa, 20.5%, and 76.3 HV, respectively.

scholarly journals Grain Size Effect of the γ Phase Precipitation on Martensitic Transformation and Mechanical Properties of Ni–Mn–Sn–Fe Heusler Alloys

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2339
Author(s):  
Jinpei Guo ◽  
Minting Zhong ◽  
Wei Zhou ◽  
Yajiu Zhang ◽  
Zhigang Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Martensitic Transformation ◽  
Annealing Time ◽  
Volume Fraction ◽  
Heusler Alloys ◽  
Coarse Grained ◽  
Dual Phase ◽  
Average Grain Size ◽  
Stress Hysteresis

Isothermal annealing of a eutectic dual phase Ni–Mn–Sn–Fe alloy was carried out to encourage grain growth and investigate the effects of grain size of the γ phase on the martensitic transformation behaviour and mechanical properties of the alloy. It is found that with the increase of the annealing time, the grain size and volume fraction of the γ phase both increased with the annealing time predominantly by the inter-diffusion of Fe and Sn elements between the γ phase and the Heusler matrix. The isothermal anneals resulted in the decrease of the e/a ratio and suppression of the martensitic transformation of the matrix phase. The fine γ phase microstructure with an average grain size of 0.31 μm showed higher fracture strength and ductility values by 28% and 77% compared to the coarse-grained counterpart with an average grain size of 3.31 μm. The fine dual phase microstructure shows a quasi-linear superelasticity of 4.2% and very small stress hysteresis during cyclic loading, while the coarse dual phase counterpart presents degraded superelasticity of 2.6% and large stress hysteresis. These findings indicate that grain size refinement of the γ phase is an effective approach in improving the mechanical and transformation properties of dual phase Heusler alloys.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

scholarly journals Development of Al–Mg–Si alloy performance by addition of grain refiner Al–5Ti–1B alloy

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110294
Author(s):  
Khaled Abd El-Aziz ◽  
Emad M Ahmed ◽  
Abdulaziz H Alghtani ◽  
Bassem F Felemban ◽  
Hafiz T Ali ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Testing Machine ◽  
Dendritic Structure ◽  
Grain Refiner ◽  
Corrosion Properties ◽  
Average Grain Size ◽  
Structural Applications ◽  
Alloy Addition

Aluminum alloys are the most essential part of all shaped castings manufactured, mainly in the automotive, food industry, and structural applications. There is little consensus as to the precise relationship between grain size after grain refinement and corrosion resistance; conflicting conclusions have been published showing that reduced grain size can decrease or increase corrosion resistance. The effect of Al–5Ti–1B grain refiner (GR alloy) with different percentages on the mechanical properties and corrosion behavior of Aluminum-magnesium-silicon alloy (Al–Mg–Si) was studied. The average grain size is determined according to the E112ASTM standard. The compressive test specimens were made as per ASTM: E8/E8M-16 standard to get their compressive properties. The bulk hardness using Vickers hardness testing machine at a load of 50 g. Electrochemical corrosion tests were carried out in 3.5 % NaCl solution using Autolab Potentiostat/Galvanostat (PGSTAT 30).The grain size of the Al–Mg–Si alloy was reduced from 82 to 46 µm by the addition of GR alloy. The morphology of α-Al dendrites changes from coarse dendritic structure to fine equiaxed grains due to the addition of GR alloy and segregation of Ti, which controls the growth of primary α-Al. In addition, the mechanical properties of the Al–Mg–Si alloy were improved by GR alloy addition. GR alloy addition to Al–Mg–Si alloy produced fine-grained structure and better hardness and compressive strength. The addition of GR alloy did not reveal any marked improvements in the corrosion properties of Al–Mg–Si alloy.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

LiNiO2 Thin Films Fabricated by Diffusion of Li on Ni Tapes

2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Grain Size ◽  
Sol Gel ◽  
Surface Oxidation ◽  
Cold Isostatic Pressing ◽  
Tube Furnace ◽  
Treatment Conditions ◽  
Average Grain Size ◽  
Cold Rolling And Annealing

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.

Microstructures and Mechanical Properties of AZ61 Mg Alloy Processed by Equal Channel Angular Pressing

2012 ◽  
Vol 468-471 ◽  
pp. 2124-2127 ◽  
Author(s):  
Shao Feng Zeng ◽  
Kai Huai Yang ◽  
Wen Zhe Chen
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Equal Channel Angular Pressing ◽  
Uniform Elongation ◽  
Considerable Decrease ◽  
Angular Pressing ◽  
Az61 Magnesium Alloy ◽  
Average Grain Size ◽  
Microstructures And Mechanical Properties ◽  
Bimodal Grain Size

Equal channel angular pressing (ECAP) was applied to a commercial AZ61 magnesium alloy for up to 8 passes at temperatures as low as 473K. Microstructures and mechanical properties of as-received and ECAP deformed samples were investigated. The microstructure was initially not uniform with a “bimodal” grain size distribution but became increasingly homogeneous with further ECAP passes and the average grain size was considerably reduced from over 26 μm to below 5 μm. The ultimate tensile strength (UTS) decreases clearly after one pass, but increases significantly up to two passes, and then continuously slowly decreases up to six passes, and again increases slightly up to eight passes. In contrast, the uniform elongation increased significantly up to 3 passes, followed by considerable decrease up to 8 passes. These observations may be attributed to combined effects of grain refinement and texture development.

Microstructural Control of Ductile Crack Propagation in TMCP HSLA Pipeline Steels

2014 ◽  
Vol 922 ◽  
pp. 568-573
Author(s):  
Victor Carretero Olalla ◽  
N. Sanchez Mouriño ◽  
Philippe Thibaux ◽  
Leo Kestens ◽  
Roumen H. Petrov
Keyword(s):  
Grain Size ◽  
Crack Propagation ◽  
Volume Fraction ◽  
Main Role ◽  
Charpy Test ◽  
Initiation And Propagation ◽  
Average Grain Size ◽  
Main Disadvantage ◽  
Steel Grades ◽  
Increasing Demand

Control of ductile fracture propagation is one of the major concerns for pipeline industry, particularly with the increasing demand of new control rolled steel grades required to maintain integrity at high operational pressures. The objective of this research is to understand which microstructural features govern crack propagation, and to analyse the effect of two of them (average grain size, and volume fraction of pearlite). The main disadvantage during classical Charpy test was to discriminate the crack initiation and propagation energy during fracture of a notched sample. The initiation appears to be caused by the stress state in the neighbouring of Ti-containing precipitates or pearlite particles (no presence of M/A constituents or MnS inclusions was detected in the evaluated grades), propagation-arrest of the crack is assumed to play the main role concerning the control of fracture. Our approach to characterize the fracture resistance is to measure the energy absorbed during the crack propagation stage by means of load-displacement curves obtained via instrumented Charpy test. It was observed that the energy absorbed during crack propagation is not influenced by the average grain size but by the fraction and the morphological (banded-not banded) distribution of second pearlitic phase. This suggests that a different approach to characterize the heterogeneities in grain size clustering might be followed to correlate the energy measured during crack propagation and the morphological features of the steel.

Study on Dynamic Recrystallization Behavior in Deformed Austenite of 52100 Steel by Using JMAK-Model

2013 ◽  
Vol 275-277 ◽  
pp. 1833-1837
Author(s):  
Ke Lu Wang ◽  
Shi Qiang Lu ◽  
Xin Li ◽  
Xian Juan Dong
Keyword(s):  
Grain Size ◽  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
True Strain ◽  
Strain And Strain Rate ◽  
Average Grain Size ◽  
Dynamic Recrystallization Behavior ◽  
Simulation And Experiment ◽  
Good Agreement

A Johnson-Mehl-Avrami-Kolmogorov (JMAK)-model was established for dynamic recrystallization in hot deformation process of 52100 steel. The effects of hot deformation temperature, true strain and strain rate on the microstructural evolution of the steel were physically studied by using Gleeble-1500 thermo-mechanical simulator and the experimental results were used for validation of the JMAK-model. Through simulation and experiment, it is found that the predicted results of DRX volume fraction, DRX grain size and average grain size are in good agreement with the experimental ones.

scholarly journals Influence of Steel Grain Size on Residual Stress in Grinding Processing

2010 ◽  
Vol 638-642 ◽  
pp. 2389-2394 ◽  
Author(s):  
Masahide Gotoh ◽  
Katsuhiro Seki ◽  
M. Shozu ◽  
Hajime Hirose ◽  
Toshihiko Sasaki
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Stress State ◽  
Mechanical Grinding ◽  
Fine Grained ◽  
Residual Stress State ◽  
Analysis Methods ◽  
Average Grain Size ◽  
Fine Grained Steels

The fine-grained rolling steels NFG600 and the conventional usual rolling steels SM490 were processed by sand paper polishing and mechanical grinding to compare the residual stress generated after processing. The average grain size of NFG600 and SM490 is 3 μm and 15μm respectively. Therefore improvement of mechanical properties for such fine-grained steels is expected, it is important to understand the residual stress state of new fine-grained materials with processing. In this study, multi axial stresses of two kinds of specimens after polishing and grinding were measured by three kinds of analysis methods including cos-ψ method. As a result, as for σ33, the stress of NFG was compression, though that of SM490 was tension.

Sign in / Sign up

Export Citation Format

Share Document