Effect of Stainless Steel Flakes Content on Mechanical Properties and Microstructure of Cast 96.66% Pure Aluminum

2018 ◽  
Vol 21 ◽  
pp. 11-19
Author(s):  
Georgios V. Seretis ◽  
Aikaterini K. Polyzou ◽  
Dimitrios E. Manolakos ◽  
Christopher G. Provatidis

Stainless steel flakes-reinforced cast aluminum matrix composites were produced using aluminum alloy of 96.66% purity as matrix material and different steel flakes contents as reinforcements. Aluminum matrix specimens with no steel flakes fillers addition were also produced for performance comparison. All specimens were cast into a slightly heated rectangular quenched steel mold, the temperature of which was 35 °C. Both matrix aluminum specimens and aluminum matrix composite specimens underwent tensile and bending tests as well as hardness measurements and microstructural investigation. As observed through microstructural examination, the interdendritic regions do not seem to be affected by steel flakes addition on their at% chemical composition, which remains Al:Fe:Mn:Mg ; 92.28:3.75:2.96:1.01, but only on their size. An increase of the flexure strength of about 20% was achieved by steel flakes-reinforcement of the matrix aluminum. In the case of the highest wt% addition, groups of steel flakes of high directivity towards solidification kernels were observed. These steel flakes group formations resulted in an impressive hardness increase, performing as hard support elements.

2017 ◽  
Vol 15 ◽  
pp. 26-35 ◽  
Author(s):  
Georgios V. Seretis ◽  
Georgios Kouzilos ◽  
Aikaterini K. Polyzou ◽  
Dimitrios E. Manolakos ◽  
Christopher G. Provatidis

Recently, many studies on the production of graphite/graphene reinforced aluminum-matrix composites using different fabrication methods, such as powder or semi-powder method, have been performed. However, cast aluminum/graphite or aluminum/graphene composites have not been widely investigated and the research on this production method mainly focuses on 3D graphite particle reinforcements. In this study, the use of a 2D graphene structure, i.e. graphene nanoplatelets (GNPs), in the production of cast Al/GNP composites is investigated. Graphene nanoplatelets reinforced cast aluminum matrix composites were produced using aluminum alloy as matrix material and different graphene nanoplatelets contents. Specimens were cast into a heated rectangular steel mold, the temperature of which was 100°C. All specimens underwent tensile and bending tests as well as hardness measurements and microstructural investigation. Ultimate Tensile Strength (UTS) was considerably increased, simultaneously with a slight decrease of elongation at break, in the case of 0.1 wt% graphene nanoplatelets addition. Regarding bending performance, a slight increase was observed as well. The flexural behavior for 0.1 wt% graphene nanoplatelets addition was exactly the same with the matrix material. The graphene nanoplatelets content found to affect both the surface and the chemical composition of the interdendritic region. After 0.1 wt%, further increase of the wt% graphene nanoplatelets content lead to formation of aluminum carbides (Al4C3) at the grain boundaries, with a consequent drop on the mechanical performance of the Al/GNPs composite.


2017 ◽  
Vol 52 (1) ◽  
pp. 123-134 ◽  
Author(s):  
Mohammad Senemar ◽  
Behzad Niroumand ◽  
Ali Maleki ◽  
Pradeep K Rohatgi

In this study, in situ aluminum matrix composites were synthesized through pyrolysis of high temperature vulcanization silicone in commercially pure aluminum melt. For this purpose, 1 to 4 wt% of high temperature vulcanization silicone was added to a vortex of molten aluminum at 750℃ and the resulting slurries were cast in steel dies. Microstructure, hardness, and tensile properties of the as-cast samples were examined at ambient and high temperatures. The results revealed the in situ formation and distribution of reinforcement particles in the matrix. Energy-dispersive X-ray analysis indicated that the formed reinforcement particles consisted of O and Si elements. This confirms the in situ reinforcement formation by pyrolysis of high temperature vulcanization silicone in the melt. The size of the in situ formed particles was mostly in the range of 200–2000 nm. It was shown that the composites synthesized by the addition of 4 wt% high temperature vulcanization had the highest mechanical properties both at ambient and high temperatures. Room temperature hardness, tensile strength, and yield strength of this sample were increased by about 50%, 23%, and 19% compared to the monolithic sample, respectively.


Alloy Digest ◽  
1997 ◽  
Vol 46 (12) ◽  

Abstract This pure aluminum matrix composite contains 60 volume% alumina. The aluminum ceramic fiber is Nextel 610. The fiber effects the longitudinal direction, resulting in a high longitudinal specific modulus and a specific strength with good off-axis properties. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive and shear strength. It also includes information on corrosion resistance as well as casting. Filing Code: AL-344. Producer or source: 3M.


2021 ◽  
Vol 87 (5) ◽  
pp. 34-42
Author(s):  
N. B. Podymova ◽  
I. E. Kalashnikov ◽  
L. I. Kobeleva

One of the most critical manufacturing defects of cast metal-matrix composites is a non-uniform porosity distribution over the composite volume. Unevenness of the distribution leads not only to local softening, but also plays a key role in the evolution of the damage process under the external loads. The goal of the study is to apply a new laser-ultrasonic method to in-situ study of a local porosity in reactive cast aluminum-matrix composites. The proposed method is based on statistical analysis of the amplitude distribution of backscattered broadband pulses of longitudinal ultrasonic waves in the studied materials. Laser excitation and piezoelectric detection of ultrasound were carried out using a laser-ultrasonic transducer. Two series of reactive cast aluminum-matrix composites were analyzed: reinforced by in situ synthesized Al3Ti intermetallic particles in different volume concentrations and by Al3Ti added with synthetic diamond nanoparticles. It is shown that for both series of the composites, the amplitude distribution of backscattered ultrasonic pulses is approximated by the Gaussian probability distribution applicable for statistics of large number of independent random variables. The empirical dependence of the half-width of this distribution on the local porosity in composites of two series is approximated by the same nearly linear function regardless of the size and fraction of reinforcing particles. This function was used to derive the formula for calculation of the local porosity in the studied composites. The developed technique seems to be promising in revealing potentially dangerous domains with high porosity in reactive-cast metal-matrix composites.


2021 ◽  
Vol 2021 (10) ◽  
pp. 1369-1374
Author(s):  
Yijin Chen ◽  
Yu. A. Kurganova ◽  
A. I. Plokhikh ◽  
S. D. Karpukhin ◽  
S. P. Shcherbakov

2020 ◽  
Vol 72 (10) ◽  
pp. 1147-1152
Author(s):  
Ömer Savaş

Purpose This study aims to investigate the production and abrasive wear rate of functionally graded TiB2/Al composites. TiB2 particles have been spontaneously formed in liquid matrix using in situ technique. The properties of composites such as hardness, abrasive wear rate and microstructure have been examined. Design/methodology/approach In situ TiB2 reinforcement phase was synthesized by using a liquid Al–Ti–B system. A semi-solid composite (Al(l)-TiB2(s)) prepared at 900°C was solidified under a centrifugal force to both grade functionally and give the final shape to materials. Abrasive wear test of materials was conducted using the pin-on-disk method at room temperature. The wear tests were carried out with two different loads of 1 Newton (N) and 2 N, a sliding velocity of 3.5 m s−1 and a sliding distance of 75 m. Findings This research provided the following findings; TiB2 particles can be successfully synthesized with in situ reaction technique in molten aluminum. It was determined that abrasive wear rate increases with increasing load and decreases with increasing TiB2 reinforcement content within matrix. Originality/value In previous studies, there have been many trials on the in situ production of TiB2-reinforced aluminum matrix composites. However, there are few studies on production of in situ TiB2-reinforced aluminum matrix functionally graded materials. At the same time, there is no study that the properties of composite, such as hardness and abrasive wear rate, are examined together according to centrifugal force. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0538/


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1213
Author(s):  
Dae-Young Kim ◽  
Pil-Ryung Cha ◽  
Ho-Seok Nam ◽  
Hyun-Joo Choi ◽  
Kon-Bae Lee

The nitridation-induced self-formed aluminum matrix composite (NISFAC) process is based on the nitridation reaction, which can be significantly influenced by the characteristics of the starting materials (e.g., the chemical composition of the aluminum powder and the type, size, and volume fraction of the ceramic reinforcement) and the processing variables (e.g., process temperature and time, and flow rate of nitrogen gas). Since these variables do not independently affect the nitridation behavior, a systematic study is necessary to examine the combined effect of these variables upon nitridation. In this second part of our two-part report, we examine the effect of nitrogen flow rates and processing temperatures upon the degree of nitridation which, in turn, determines the amount of exothermic reaction and the amount of molten Al in the nitridation-induced self-formed aluminum matrix composite (NISFAC) process. When either the nitrogen flow rate or the set temperature was too low, high-quality composites were not obtained because the level of nitridation was insufficient to fill the powder voids with molten Al. Hence, since the filling of the voids in the powder bed by molten Al is essential to the NISFAC process, the conditions should be optimized by manipulating the nitrogen flow rate and processing temperature.


2016 ◽  
Vol 256 ◽  
pp. 81-87 ◽  
Author(s):  
Ju Fu Jiang ◽  
Ying Wang ◽  
Shou Jing Luo

Semisolid slurries of 7075 aluminum matrix composite reinforced with nano-sized SiC particles were fabricated by ultrasonic assisted semisolid stirring (UASS) method. Rheoforming and thixoforming of typical cylindrical parts were investigated. The results show that high-quality semisolid slurries with spheroidal solid grain of 38 µm were fabricated by UASS. The nano-sized SiC particles were dispersed uniformly due to transient cavitation and acoustic streaming of ultrasonic wave and high and controllable viscosity of semisolid slurry. Typical cylindrical composite parts with good surface quality and complete filling were rheoformed and thixoformed successfully. Ultimate tensile strength (UTS) of the rheoformed and thixoformed composite parts are enhanced due to addition of nano-sized SiC particles. However, elongation decreased as compared to those of the matrix parts. Maximum UTS of 550 MPa was achieved in the thixoformed composite part with T6 treatment. Increase of dislocation density around the reinforcement particles leads to improvement of the strength and wear resistance of the composite.


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