Fabrication and characterization of TiB2-reinforced functionally graded aluminum matrix material

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/

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Gaurav Gautam ◽  
Anita Mohan

Particulate aluminum matrix composites (PAMCs) with different volume percent of Al3Zr particles have been developed by direct melt reaction (DMR). Wear and friction have been studied in detail for all compositions under dry sliding conditions. Results indicate that the wear rate, normalized wear rate, and wear coefficient of PAMCs decrease continuously with increase in volume percent of Al3Zr particles, however, with applied load and sliding distance, wear continuously increases. Wear rate and wear coefficient with sliding velocity initially decrease for all compositions, attains minima, and then increase sharply. However, coefficient of friction shows increasing trend with composition and sliding velocity but with load it shows a decreasing trend and with distance slid it fluctuates within a value of ±0.025. At low load and sliding velocity three-dimensional (3D)-profilometer, scanning electron microscope (SEM), and debris studies show low Ra values and mild wear dominated by oxidative nature, whereas at high loads and sliding velocities high Ra values and wear nature change to severe wear with mixed mode (oxidative–metallic) and surface with deep grooves is observed. Further, it is also important to note from morphological studies that refinement of matrix phase takes place with in situ formation of Al3Zr particles, which helps to improve hardness and tensile properties finally contributing to low wear rate.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jiaqi Pan ◽  
Xiaoshan Liu ◽  
Guoqiu He ◽  
Bin Ge ◽  
Peiwen Le ◽  
...  

Purpose The purpose of this paper is to understand the effect of particle content, applied load and sliding speed on the tribological properties of A356-SiCP composites manufactured using a newly developed vacuum stir casting technique. Design/methodology/approach A356 alloy reinforced with 10, 15 and 20 vol% SiC particles was prepared by vacuum stir casting. Tribological tests were carried out on block-on-ring tribometer under dry sliding conditions, room temperature. Wear mechanism was investigated by scanning electron microscope and energy dispersion spectrum. Findings SiCP is homogeneously dispersed in the matrix. The increase in SiCP content decrease wear rate, but it leads to an increase in coefficient of friction. The wear rate increase and friction coefficient present different variation trends with increasing load. For A356-20%SiCP composite, when the load is less than 10 MPa, wear rate and friction coefficient under sliding speed of 400 rpm are lower than those of 200 rpm. Wear mechanism transition from abrasion, oxidation, delamination, adhesion to plastic flow as load and sliding speed increasing. Practical implications Results of this study will help guide the use of A356-SiCP in many automotive products such as brake rotors, brake pads, brake drums and pistons. Originality/value There are few paper studies the effect of particle content, applied load and sliding speed on the tribological properties of A356-SiCP composites. Aluminum matrix composites with uniform distribution of reinforcing particles were successfully prepared by using the newly developed vacuum stir casting technique.


2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/


2015 ◽  
Vol 787 ◽  
pp. 583-587 ◽  
Author(s):  
V. Mohanavel ◽  
K. Rajan ◽  
K.R. Senthil Kumar

In the present study, an aluminum alloy AA6351 was reinforced with different percentages (1, 3 and 5 wt %) of TiB2 particles and they were successfully fabricated by in situ reaction of halide salts, potassium hexafluoro-titanate and potassium tetrafluoro-borate, with aluminium melt. Tensile strength, yield strength and hardness of the composite were investigated. In situ reaction between the inorganic salts K2TiF6 and KBF4 to molten aluminum leads to the formation of TiB2 particles. The prepared aluminum matrix composites were characterized using X-ray diffraction and scanning electron microscope. Scanning electron micrographs revealed a uniform dispersal of TiB2 particles in the aluminum matrix. The results obtained indicate that the hardness and tensile strength were increased with an increase in weight percentages of TiB2 contents.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
M. Poornesh ◽  
Shreeranga Bhat ◽  
E.V. Gijo ◽  
Pavana Kumara Bellairu

PurposeThis article aims to study the tensile properties of a functionally graded composite structure with Al–18wt%Si alloy as the matrix material and silicon carbide (SiC) particles as the reinforcing element. More specifically, the study's primary objective is to optimize the composition of the material elements using a robust statistical approach.Design/methodology/approachIn this research, the composite material is fabricated using a combination of stir casting and the centrifugal casting technique. Moreover, the test specimen required to study the tensile strength are prepared according to the ASTM (American Society for Testing and Materials) standards. Eventually, optimal composition to maximize the tensile property of the material is determined using the mixture design approach.FindingsThe investigation results imply that the addition of the SiC plays a crucial role in increasing the tensile strength of the composite. The optical microstructural images of the composite show the adequate distribution of the reinforcing particles with the matrix. The proposed regression model shows better predictability of tensile strength. In addition, the methodology aids in optimizing the mixture component values to maximize the tensile strength of the produced functionally graded composite structure.Originality/valueLittle work has been reported so far where a hypereutectic Al–Si alloy is considered the matrix material to produce the composite structure. The article attempts to make a composite structure by using a combination of stir casting and centrifugal casting. Furthermore, it employs the mixture design to optimize the composition and predict the model of the study, which is one of a kind in the field of material science.


1999 ◽  
Vol 14 (11) ◽  
pp. 4246-4250
Author(s):  
H. J. Brinkman ◽  
J. Duszczyk ◽  
L. Katgerman

A method is described for the production of dense aluminum matrix composites from elemental powders in one processing step by reactive hot pressing (RHP). It encompasses both the exothermic conversion of reactants to composite product and the following hot compaction of the porous composite product. The RHP method described in this paper takes into account the gas evolution accompanying the exothermic process, ensures complete conversion of reactants, and avoids adverse reactions between aluminum matrix and graphite tooling material. In situ sample temperature measurements enable proper process control, in particular the timing of the full densification step of the hot reaction product.


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