Microstructure and mechanical properties of Fe–Al–Nb–B alloys

MRS Advances ◽  
2017 ◽  
Vol 2 (25) ◽  
pp. 1353-1359 ◽  
Author(s):  
Shahbaz Ahmed Azmi ◽  
Alena Michalcová ◽  
Lucia Senčekova ◽  
Martin Palm

ABSTRACTDoping of Fe–Al–Nb alloys with boron results in precipitation of stable C14 Laves phase Nb(Fe,Al)2 instead of metastable Heusler phase Fe2AlNb as in case of the ternary system. The boron stimulated precipitation of the Laves phase leads to preferential precipitation of the Laves phase along grain boundaries and – with higher supersaturation of Nb in the Fe-Al matrix – to an even distribution of additional precipitates within the grains. Though these microstructures seem to be more favourable than in the boron-free alloys, which show an uneven distribution of rather large Laves phase precipitates, no marked strengthening effect by the Laves phase in the Fe–Al–Nb–B alloys is observed.

2007 ◽  
Vol 546-549 ◽  
pp. 323-326 ◽  
Author(s):  
Yong Liu ◽  
Guang Yin Yuan ◽  
Chen Lu ◽  
Wen Jiang Ding

The microstructure and mechanical properties of Mg95.9Zn3.5Gd0.6 and Mg94.4Zn3.5Gd0.6Cu1.5 alloys reinforced by icosahedral quasicrystalline phase (I-phase) and Laves phase has been studied after extrusion at 573K. Extrusion can significantly refined the I-phase and Laves phase, and the strengthening effect of I-phase and Laves phase has been analyzed. Large volume of icosahedral phase in Mg95.9Zn3.5Gd0.6 has important role in its high UTS and elongation due to strong bonding effect at the I-phase/matrix interface for low interface energy. The Laves phase with cubic topological and close-packed structure in Mg94.4Zn3.5Gd0.6Cu1.5 alloy result in the higher heat resistance at elevated temperatures.


2022 ◽  
Vol 905 ◽  
pp. 44-50
Author(s):  
Li Wang ◽  
Ya Ya Zheng ◽  
Shi Hu Hu

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.


2013 ◽  
Vol 765 ◽  
pp. 418-422 ◽  
Author(s):  
Ram Naresh Rai ◽  
A.K. Prasada Rao ◽  
G.L. Dutta ◽  
M. Chakraborty

The forming behaviour of in-situ Al-TiC composites was investigated by comparing microstructure and mechanical properties of as-cast, forged and rolled specimens. The microstructures of forged and rolled specimens reveal uniform distribution of the TiC particles, which are responsible for the enhancement of the tensile strength of the composite. The formed samples were found to be crack free. This feature is very likely to be due to good interface bonding of uniformly dispersed sub-micron size TiC particles with the Al matrix.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 568
Author(s):  
Xinwei She ◽  
Xianquan Jiang ◽  
Bao Qi ◽  
Kang Chen

The effect of Er on microstructure and mechanical properties of the 5052 aluminum alloy with a big width-to-thickness ratio was investigated by a metallurgical microscope, scanning electron microscope and tensile testing machine. The results showed that the precipitates were slightly refined after Er addition and Al3Fe was transformed into Al6Fe and AlEr with/without a small amount of Fe or Si. The effect of Er on grain refinement was related to its content. When Er content was lower or higher than 0.4%, the grain would coarsen. Homogenization could refine the grain by controlling Er content and distribution in the Al matrix. Long time homogenization at high temperature would significantly reduce the strength of the 5052 aluminum alloy and 5052 aluminum alloys with low Er content, but help to improve the plasticity of those with high Er content. The ultimate tensile strength, yield strength and elongation of the as-cast 5052 aluminum alloy were 197 MPa, 117 MPa and 22.5% respectively. The strength was the highest, when Er content was 0.4 wt. % and the elongation was the best at 0.1 wt. % Er content.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2046 ◽  
Author(s):  
Yi Jing ◽  
Hongbing Yuan ◽  
Zisheng Lian

ZrB2–HfC ceramics have been fabricated using the liquid phase sintering technique at a sintering temperature as low as 1750 °C through the addition of Ni. The effects of HfC addition on the microstructure and mechanical properties of ZrB2–based ceramics have been investigated. These ceramics were composed of ZrB2, HfC, Ni, and a small amount of possible (Zr, Hf)B2 solid solution. Small HfC grains were distributed among ZrB2 grain boundaries. These small grains could improve the density of ZrB2–based ceramics and play a pinning role. With HfC content increasing from 10 wt % to 30 wt %, more HfC grains were distributed among ZrB2 grain boundaries, leading to weaker interface bonding among HfC grains; the relative density and Vickers hardness increased, and flexural strength and fracture toughness decreased. The weak interface bonding for 20 and 30 wt % HfC contents was the main cause of the decrease in both flexural strength and fracture toughness.


2001 ◽  
Vol 35 (17) ◽  
pp. 1570-1586
Author(s):  
Changwook Son ◽  
Ikwoo Kim ◽  
Ikmin Park ◽  
Kyung-Mox Cho ◽  
Ildong Choi

2000 ◽  
Vol 2000.3 (0) ◽  
pp. 393-394
Author(s):  
Kiyoshi MIZUUCHI ◽  
Masami SUGIOKA ◽  
Masao ITAMI ◽  
Yoshihira OKANDA ◽  
Kenichi HAMADA ◽  
...  

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