Microstructural and Mechanical Characterization of ARB AZ31

2013 ◽  
Vol 765 ◽  
pp. 403-407 ◽  
Author(s):  
Friederike Schwarz ◽  
Katja Lange ◽  
Lutz Krüger ◽  
Rudolf Kawalla ◽  
Stephan Reichelt
Keyword(s):  
Grain Size ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Basal Texture ◽  
Electron Backscattered Diffraction ◽  
Roll Bonding ◽  
Average Grain Size ◽  
Twin Roll Cast ◽  
Twin Roll

In this work the influence of accumulative roll bonding (ARB) process on the microstructure and the mechanical characteristic is investigated. Therefore, AZ31 magnesium sheets were successfully deformed through ARB for a maximum of three passes. Twin roll cast sheets and twin roll cast sheets with subsequent heat treatment (480 °C, 1 h) were used as initial materials. After one ARB pass, the highest microstructure changes were measured. Electron backscattered diffraction (EBSD) reveals a bimodal microstructure with an average grain size of ~1µm. In comparison to the initial material a strong basal texture was measured. The significant refinement of grain size after severe plastic deformation cause an increase of tensile and compressive strength, e.g. rising yield stress and ultimate tensile strength of 42% and 15%, respectively. However, the maximum formability remains nearly at the same level. Further ARB passes do not improve the mechanical characteristics further.

Metallographic, Structural and Mechanical Characterization of a Low Density Fe-Mn-Al-C Steel Microalloyed with Ti/B in As-Cast and Homogenized Conditions

MRS Advances ◽  
2018 ◽  
Vol 3 (64) ◽  
pp. 3971-3978 ◽  
Author(s):  
O.E. Villanueva-Perez ◽  
I. Mejía ◽  
V. García-García ◽  
A. Bedolla-Jacuinde
Keyword(s):  
Grain Size ◽  
Mechanical Characterization ◽  
The Other ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Other Hand ◽  
Average Grain Size ◽  
Cast Condition

ABSTRACTLow density (LD) steels have shown particular characteristics in terms of mechanical properties and microstructure, since they have high strength, high ductility and density reduction up to 18%. On the other hand, the addition of microalloying elements such as Ti and B generate hardening by solid solution and precipitation, as well as grain refinement effect. LD steels generate nano-sized kappa phase precipitated from the austenite matrix, and these advanced steels can reach strength and elongation up to 780 MPa and 60%, respectively. The main objective of this research work is the metallographic, structural and mechanical characterization of a LD steel microalloyed with Ti/B in as-cast and -homogenized conditions. For this purpose a Fe-27Mn-7Al-1.2C (%wt) LD steel microalloyed with Ti/B was melted in a vacuum-induction furnace and cast in metallic mold. LD-Ti/B steel samples were homogenized at 1100 °C during 20, 50, 100, 150 and 200 minutes followed by water quenching. Metallographic, structural and mechanical characterization was carried out by optical (LOM) and scanning electron (SEM) microscopy, X-ray diffraction (XRD) and microhardness Vickers testing (HV10), respectively. In general, results showed a typical dendritic microstructure with average grain size of 1256 μm in the as-cast condition. On the other hand, the as-homogenized condition showed an austenitic equiaxial microstructure with average grain size from 164 to 940 μm. Austenite, ferrite and kappa phases were detected by X-ray diffraction (XRD). Also, second-phase particles such as AlN, TiC and MnS were detected by LOM and SEM-EDS analysis. LD steel microalloyed with Ti/B exhibited the highest microhardness Vickers value (235 HV10) in the as-cast condition, whilst in the as-homogenized condition microhardness gradually decreases from 223 to 198 HV10 as holding time increases.

scholarly journals Influence of homogenization on the microstructure, mechanical properties and texture of the twin-roll cast AA8006 sheet processed by accumulative roll-bonding

2020 ◽  
Vol 326 ◽  
pp. 05003
Author(s):  
Miroslav Karlík ◽  
Petr Homola ◽  
Peter Sláma ◽  
Jiří Čapek ◽  
Petr Harcuba
Keyword(s):  
Mechanical Properties ◽  
Accumulative Roll Bonding ◽  
Rolling Texture ◽  
Tensile Tests ◽  
Grain Structure ◽  
Electron Backscattered Diffraction ◽  
Roll Bonding ◽  
Fine Grain ◽  
Twin Roll Cast ◽  
Twin Roll

Unhomogenized and homogenized AA8006 (Al-Fe-Mn-Si) alloy sheets twin-roll cast to strip 8.5 mm thick, processed by accumulative roll-bonding (ARB) on 2 mm thick sheets up to 6 cycles were studied. The microstructure was characterized by means of scanning and transmission electron microscopy and electron backscattered diffraction (EBSD), mechanical properties were monitored by hardness measurements and tensile tests. The macroscopic texture was determined by X-ray diffraction. The initial texture of the unhomogenized sheet is rotated cubic {001}<110> combined with recrystallization R texture {011}<211>, while the homogenized sheet has a cubic texture {001}<100> with remaining rolling component C {112}<111>. One ARB cycle leads to the formation of low-angle grain boundaries (LAGB) in original coarser grains and to a low angle rotation of the subgrains bounded by LAGB. After the 3rd and 6th ARB cycle unhomogenized and homogenized sheets show a common rolling texture of cold-rolled aluminium. The thermal stability of sheets processed by 6 ARB cycles was tested by isochronal annealing for 30 min up to 450°C. The homogenized sheet starts to recrystallize at 250°C, while the fine grain structure of the unhomogenized sheet is thermally stable up to 400°C.

scholarly journals Crystallography of grain refinement in cast zinc–copper alloys

2015 ◽  
Vol 48 (3) ◽  
pp. 890-900 ◽  
Author(s):  
Zhilin Liu ◽  
Dong Qiu ◽  
Feng Wang ◽  
John A. Taylor ◽  
Mingxing Zhang
Keyword(s):  
Grain Size ◽  
Grain Refinement ◽  
Copper Alloys ◽  
Diffraction Method ◽  
Electron Backscattered Diffraction ◽  
Grain Coarsening ◽  
Cu Content ◽  
Edge Matching ◽  
Average Grain Size ◽  
Cast Alloys

Adding the peritectic forming element Cu effectively reduced the average grain size of cast Zn by over 85%. At a specified cast condition, the smallest grain size was obtained at 2 wt% Cu addition. A further increase in Cu content led to grain coarsening in the cast Zn–Cu alloys. Although the solute effect of Cu was predominately responsible for the grain refinement through restriction of the grain growth, it was found that the variation of grain size is also closely related to the formation of the pro-peritectic phase, ∊-CuZn4. Crystallographic calculations using the edge-to-edge matching model showed low interatomic misfit and interplanar mismatch between Zn and the ∊-CuZn4phase. In addition, a reproducible h.c.p.–h.c.p. (h.c.p. denotes hexagonal close-packed) orientation relationship between Zn and the ∊-CuZn4particles (located within the Zn grain centres) was also experimentally determined using the electron backscattered diffraction method. This indicated the high potency of the pro-peritectic ∊-CuZn4particles as effective heterogeneous nucleation sites for η-Zn, which further refined the Zn grains. However, when the Cu content was over 2.0 wt%, formation of large ∊-CuZn4particles resulted in grain coarsening of the cast alloys.

Characterization of Medium Density Particleborads Using Agricultural Residues

2015 ◽  
Vol 1088 ◽  
pp. 656-659
Author(s):  
Ivaldo D. Valarelli ◽  
Rosane A.G. Battistelle ◽  
Barbara Stolte Bezerra ◽  
Luiz A. Melgaço N. Branco ◽  
Eduardo Chahud ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Castor Oil ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Raw Materials ◽  
Construction Materials ◽  
Agricultural Residues ◽  
Medium Density ◽  
Polyurethane Resin

In recent years the production of products derived from wood and bamboo are increasing, due to the search for a more rational exploitation of these raw materials. Amongst these products, the particleboards production combine sustainability and rationality in the use of these materials. In this context, this work has the objective to study the application of alternative raw materials in the manufacture of Medium Density Particleboards (MDP), using residues from industrial processimg of coffee and bamboo. MDP had been produced with particles of giganteus bamboo of the Dendrocalamus species and particle of coffee rind in the intermediate layer of the particleboard, bonded with polyurethane resin based on castor oil. The physical and mechanical characterization was carried out accordingly to NBR 14810-3 (2006). The physical properties evaluated were: of water absorption for 2h and 24h; thickness swallowing for 2h and 24h; density, humidity content. The mechanical properties evaluated were: Tensile strength, static bending (MOR and MOE). The results were compared with NBR 14810-2 (2006) and also with the ANSI A208-1 (1993). The physical performance of these particleboards was below the values recommend by the Brazilian norm. Also the mechanical characteristics are not improve, demonstrating that the inclusion of coffee rind did not benefit the physical characteristics and nor the mechanical ones. However it can be used as construction materials for partitions and ceiling panels.

Growth Kinetics and Mechanical Characterization of a Hard Boron Coating on a Tool Steel

2017 ◽  
Vol 380 ◽  
pp. 29-34 ◽  
Author(s):  
D. Sánchez Huerta ◽  
N. López Perrusquia ◽  
I. Hilerio Cruz ◽  
M.A. Doñu Ruiz ◽  
E.D. García Bustos ◽  
...  
Keyword(s):  
Activation Energy ◽  
Mechanical Characteristics ◽  
Mechanical Characterization ◽  
Chemical Elements ◽  
Thermochemical Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Optimal Classification

The mechanical characteristics are determined to a FeB/Fe2B coating applied in AISI L6 steel tool and blades make to cut paper. The thermochemical treatment was applied at temperatures of 1173, 1223 and 1273 K with permanence time of 0.5, 2 and 3 h for each temperature. The diffusion coefficient and activation energy for each phase is obtained for this boron coating on an AISI L6 steel. HRC test were made to establish the type of adherence (qualitative) and comparing with the VDI 3198 standard and the results were obtaining optimal classification of HF1-HF2 in condition for 3h of the three temperatures. The result by nanoidentation show hardness of 1000 - 2000 HV as well as the Young's modulus for each present phase of the coating. Through micrographs (SEM) are showing thicknesses up to 79.52 ± 18.82 μm for FeB and 97.80 ± 20.01μm for Fe2B, a morphology sawn ́s type is evidence. Through EDS and x-ray diffraction are used to show the chemical elements formed.

Synthesis and Characterization of Plasma Synthesized Nanostructured Magnesia-Yttria Based Nanocomposites

2007 ◽  
Vol 1056 ◽  
Author(s):  
Jafar F. Al-Sharab ◽  
Rajendra Sadangi ◽  
Vijay Shukla ◽  
Bernard Kear
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Chemical Mapping ◽  
X Ray Diffraction ◽  
Fine Grained ◽  
Transmission Electron ◽  
Spray Method ◽  
Average Grain Size

ABSTRACTPolycrystalline Y2O3 is the material of choice for IR windows since it has excellent optical properties in the visible, and near infra-red band. However, current processing methods yield polycrystalline Y2O3 with large grain size (> 100 μm), which limits the hardness and erosion resistance attainable. One way to improve strength is to develop an ultra-fine grained material with acceptable optical transmission properties. To realize a fine-grained ceramic, one approach is to develop a composite structure, in which one phase inhibits the growth of the other phase during processing. In this study, Y2O3-MgO nanocomposite with various MgO content (20, 50 and 80 mol%) were synthesized using plasma spray method. Extensive characterization techniques including x-ray diffraction, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy Dispersive spectrometry (EDS) were employed to study the synthesized powder as well as the consolidated sample. Transmission Electron Microscopy, as well as EDS chemical mapping, revealed that the consolidated sample have bi-continuous MgO-Y2O3 nanostructure with an average grain size of 200 nm.

Preparation and Characterization of As-Cast and Hot-Rolled Mg-5Al-0.3Mn-1Ce Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1559-1563 ◽  
Author(s):  
Jian Li Wang ◽  
Jian Ping Li ◽  
Li Min Wang ◽  
Li Dong Wang
Keyword(s):  
Grain Size ◽  
Test Results ◽  
Casting Method ◽  
Rolled Sample ◽  
Cast Sample ◽  
Average Grain Size ◽  
Dislocation Strengthening ◽  
Hot Rolled ◽  
Mould Casting

Mg-5Al-0.3Mn-1Ce alloy was prepared by metal mould casting method. The as-cast ingot was homogenized and hot-rolled with total thickness reduction of 61% after four passes. Texture, microstructure and mechanical properties of the studied alloy were investigated. Results showed that the as-cast sample was mainly composed of a-Mg, Mg17Al12and Al11Ce3phases. Average grain size of the as-cast sample was about 500 μm. After hot-rolling, average grain size was greatly refined to about 20 μm. Further more, the long acicular Al11Ce3phase was smashed to small pieces. Tensile test results demonstrated that ultimate tensile strength and yield strength of the hot-rolled sample were improved by 65.2% and 165% respectively compared with those of the as-cast sample. Strength enhancement was attributed to grain refining strengthening and dislocation strengthening mechanisms.

Annealing Treatment for Superplastic Forming of Twin Roll Casted AZ31 Magnesium Sheet

2011 ◽  
Vol 239-242 ◽  
pp. 50-54 ◽  
Author(s):  
Guo Dong Shi ◽  
Jun Qiao
Keyword(s):  
Grain Size ◽  
Grain Growth ◽  
Mechanical Test ◽  
Dynamic Balance ◽  
Annealing Treatment ◽  
Optical Microscope ◽  
Grain Structure ◽  
Average Grain Size ◽  
Az31 Sheet ◽  
Twin Roll

Annealing treatments at 200°C, 250 °C, 300°C, and 350°C were conducted on a twin-roll casted AZ31 sheet with an initial average grain size of 10.11 mm. Microstructure and mechanical behaviors were studied by optical microscope observation and tensile mechanical test. Expermeintal results show that grain size experienced three stage evolution during 180 min annealing at each temperature: recrystallization refinement, stabilization under dynamic balance of recrystallization and grain growth, and grain growth. The minimum average grain size of 5.96 μm was achieved after 120 min annealing at 200°C. The refined grain structure causes a decrease of ultimate tensile strength and an increase of elongation, and facilitates superplastic deformation of the material.

Microstructural and Electrical Characterization of Barium Strontium Titanate Thin Films

1994 ◽  
Vol 361 ◽  
Author(s):  
Yujing Wu ◽  
Elizabeth G. Jacobs ◽  
Russell F. Pinizzotto ◽  
Robert Tsu ◽  
Hung-Yu Liu ◽  
...  
Keyword(s):  
Grain Size ◽  
Electrical Characterization ◽  
Microstructural Characterization ◽  
Plan View ◽  
Pt Electrodes ◽  
Average Grain Size ◽  
Metal Organic ◽  
Bst Thin Film ◽  
Anneal Time

ABSTRACTThe kinetics of BST thin film grain nucleation and growth caused by rapid thermal annealing have been investigated. A series of Ba0.67Sr0.33Tii0.5O3 films were deposited on Pt electrodes using a metal-organic decomposition process. The effects of anneal time and temperature on BST grain sizes were studied by altering the processing conditions during RTA. A series of films were annealed by RTA at temperatures ranging from 550°C to 950°C for times ranging from 30 to 120 seconds. Crystallographic and microstructural characterization were done using XRD and TEM. The XRD results indicated that BST grain size increased with increasing anneal temperature, but was not affected by anneal time. Plan-view TEM indicated that BST grains were imbedded in an amorphous matrix. The average grain size was on the order of 200 Å.

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