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1

Study on Microstructure and Mechanical Properties of Friction Stir Welding Joints of In-Situ Al3Zr/AA6082 Particle-Reinforced Aluminum Matrix Composites

Li Hui, Sun Caizhi, Wang Feng, Qiao Yuanpeng, Li Chuying, Xu Pinyi, Zatulovskiy Andrii, Shcheretskyi Volodymyr

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

907--919

EN

In this paper, the Al-K2ZrF6 reaction system was used to prepare in-situ Al3Zr/AA6082 particle-reinforced aluminum matrix composites by electromagnetic stirring melt reaction method, and the friction stir welding technology was used to weld the plate. The microstructure and mechanical properties of the welded joints were studied when the rotating speed was 14000 rpm and the welding speed was 30, 50 and 70 mm/min respectively. The results show that the weld forming quality and tensile properties of the FSW joints with welding parameters of 14000 rpm and 50 mm/min are the best, the tensile strength is 142(±0.5) MPa and the elongation is 8.2%. SEM analysis shows that the particle size of the reinforcing phase in the base metal is refined to about 5-10 μm, while that in the NZ is about 1-5 μm. The grain size in the HAZ is about 20-30 μm and in the NZ is about 5-10 μm. EBSD analysis shows that the proportion of low-angle grain boundary in the NZ is 59.7% and of recrystallized grain structure is 23.65%, while the proportion of small-angle grain boundary in the HAZ is 24.35% and of recrystallized grain structure is 37.18%. It provides theoretical and experimental basis for the forming and application of friction stir welding of the composite.

2

Fabrication of Aluminum Matrix Composite Reinforced with Al0.5CoCrCuFeNi High-Entropy Alloy Particles

Kim Min Sang, Son Han Sol, Joo Gyeong Seok, Kim Young Do, Choi Hyun Joo, Kim Se Hoon

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 4

1543--1546

EN

The aluminum composite with dispersed high entropy alloy were developed by stir casting involving the powder-in-tube method. First, Al0.5CoCrCuFeNi high entropy alloy (HEA) powder was made by mechanical alloying, and the powder was extruded in a tube-type aluminum container to form HEA precursor. The extruded HEA precursor was then dispersed in the aluminum matrix via stir casting. As a result, Fe-Cr-Ni based high-entropy phases was uniformly formed in the aluminum matrix, revealing ~158, 166, 235% enhancement of tensile strength by incorporating 1, 3, and 5 wt% HEA particles, respectively.

3

Elevated-temperature tensile deformation and fracture behavior of particle-reinforced PM 8009Al matrix composite

Chen Shuang, Chen Guoqiang, Gao Pingping, Liu Chunxuan, Wu Anru, Dong Lijun, Huang Zhonghua, Ouyang Chun, Zhang Hui

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 5

art. no. e138846

EN

Tensile tests of 8009Al alloy reinforced with SiC and Al₂O₃ particles fabricated by powder metallurgy (PM) were conducted at temperatures of 250–350°C and strain rates of 0.001–0.1 s⁻¹. The ultimate tensile strength and yield strength of the samples decreased while the temperature and strain rate increased. The elongation slightly decreased at first and then increased with growing temperature because of the medium-temperature brittleness of the alloy matrix. When the strain rate was 0.1 s⁻¹, the elongation of the 8009Al/Al₂O₃ composites always decreased with an increase in temperature because of the poorly coordinated deformation and weak bonding between the matrix and Al₂O₃ particles at such a high strain rate. The work-hardening rates of the composites sharply increased to maxima and then decreased rapidly as the strain increased. Meanwhile, the 8009Al/SiCₚ composites displayed superior UTS, YS, elongation, and work-hardening rates than those of the 8009Al/Al₂O₃ composites under the same conditions. Compared to 8009Al alloys reinforced with spherical Al₂O₃ particle, 8009Al alloys reinforced with irregular SiC particles exhibited a better strengthening effect. The fracture mechanism of the 8009Al/SiCₚ composites was mainly ductile, while that of the 8009Al/Al₂O₃ composites was primarily debonding at the matrix–particle interfaces in a brittle mode.

4

Cermet composite material based on aluminothermy

Penkov I., Petkov V., Valov R.

Prace Instytutu Odlewnictwa

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2017

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Vol. 57, no. 4

293--296

EN

A new method for synthesis of cermet composite materials was developed based on aluminothermy. Employing this method a cermet composite material with a high content of AlN crystal phase was synthesized. Fine powders of aluminum and silica glass were mixed and heated in a corundum crucible for 6 hours at 1100°C in air. The X-ray diffraction analysis showed that the composite material thus synthesized contains a high concentration of AlN particles (about 33 vol. %) embedded in an aluminum silicon alloy. A small amount of Al2O3 particles (about 8 vol. %) was also found. The method proposed can also be used for synthesis of aluminum matrix composite materials containing, besides AlN, other ceramic reinforcement phases. The properties of these composite materials can be tailored by choosing an appropriate composition of the initial powder mixture for aluminothermic synthesis.

5

Correlations between stereological parameters of carbon componenet and tribological properties of heterophase composites Al-Al2O3+C

Hekner B., Myalski J.

Composites Theory and Practice

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2016

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R. 16, nr 2

67--73

EN

This paper is an attempt to describe the influence of the stereological properties of the reinforcement on the final material properties. The research was carried out on Al based composites with a heterogeneous reinforcement of Al2O3 and C. Various sizes of the carbon particle component (< 40, 80÷120, 160÷200 and < 200 µm) were applied for material manufacturing. The materials were obtained by high energy ball milling and subsequent hot pressing processes. As a result of the milling stage, a reduction in the compound size was observed. First, the real size of the carbon component, the real amount of carbon on the material surface and other properties were measured by quantitative metallography methods. Then, the correlations between the obtained stereological parameters and the tribological properties were checked. The analysis revealed that the average size of a single carbon particle and the distance between adjacent particles are the most important factors for the tribological properties of Al-Al2O3+C composite design. The larger the size of particles and the greater the distance between the particles resulted in increasing the friction coefficient value. It is related to the homogeneous distribution of the reinforcing component. However, the most surprising effect was discovered during analysis of the areal fraction of C particles. There were no clear correlations between the amount of C particles and the tribological properties. The conducted research revealed which of the analysed parameters are the most valuable for material design and predicting the final properties.

PL

W pracy dokonano oceny wpływu wielkości cząstek umacniających na właściwości tribologiczne. Badania zostały przeprowadzone na kompozytach o osnowie Al umacnianych heterofazowymi cząstkami Al2O3 oraz C. Materiały zostały wytworzone metodami wysokoenergetycznego mielenia w młynach planetarnych oraz prasowania na gorąco, stosując różne frakcje komponentu węglowego (< 40, 80÷120, 160÷200 oraz < 200 µm). W wyniku mielenia wysokoenergetycznego stwierdzono redukcję wielkości cząstek węglowych. W pierwszym etapie badań dokonano oceny podstawowych parametrów stereologicznych wytworzonych materiałów, takich jak udział C na powierzchni materiału czy średnia wielkość cząstki węgla. Następnie dokonano oceny zależności pomiędzy rzeczywistymi wartościami parametrów stereologicznych a właściwościami tribologicznymi badanych materiałów. Przeprowadzona analiza wykazała, że spośród najważniejszych czynników mających wpływ na właściwości tribologiczne kompozytów Al-Al2O3+C należy wymienić średnią wielkość pojedynczej cząstki C oraz odległość między sąsiednimi cząstkami węgla. Zwiększenie średniej wielkości cząstki, jak również jej odległości pomiędzy cząstkami skutkuje wzrostem wartości współczynnika tarcia. Jest to związane z homogenicznym rozmieszczeniem fazy węglowej w objętości kompozytu. Jednakże, najbardziej zaskakujące rezultaty zostały zaobserwowane podczas analizy udziału węgla na powierzchni kompozytu. Przeprowadzona ocena stereologiczna mikrostruktury kompozytu wykazała, które z parametrów mogą być uwzględnione i wykorzystane do określenia parametrów technologii wytwarzania oraz właściwości tribologicznych kompozytu.

6

Wear behavior of metallic and ceramic materials under electric sliding contact

Matsuyama S., Akakabe T., Ohba H.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, Spec. is

389-395

EN

To obtain lighter materials for current collectors, simple screening tests have been executed using various materials in comparison with actual sliders. As a result, titanium carbide composite with flaky graphite and aluminum alloy matrix composite reinforced with Al2O3 fibers were selected as candidates. Both materials exhibit good wear resistance under conditions without current. However, when current is supplied, the wear loss tends to increases due to transference of copper from trolley for the former and due to forming of fused alloying layer with copper, especially in rainy condition, for the latter.