Mechanical and microstructure characterization of aluminium-copper (Al-Cu) reinforced with in situ titanium diboride (TiB2)

Aluminium based in-situ metal matrix composites (MMCs) have better properties and performance when compared to ex-situ MMCs. In this research, aluminium-copper (Al-Cu) alloy was reinforced with 1 to 6wt.% titanium diboride (TiB2). Al-MMCs has been fabricated with salt route reaction process at 800 °C via potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4) salts. Al-Cu composites reinforced with 1,2, 3 and 6wt.% TiB2 then will be characterized their mechanical properties and microstructure. From results obtained, increased TiB2 contents will increased the value of tensile and hardness properties of Al-Cu alloy. The composites synthesized using in-situ techniques exhibit the presence a uniform distribution of reinforcement that tends to be fine and associated with a clean interface with the metallic matrix. In order to achieve a good mechanical and wear properties it is important to control Al3Ti phase formation during the synthesis of in situ Al-Cu/TiB2 composites

Wear properties of metal matrix composites Al-Cu and Al-Cu-TiB2

Tensile and wear properties of aluminium (Al) based metal matrix composites (MMCs) was prepared by added titanium diboride (TiB2) with in-situ technique by salt route. The salts used in this research were potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4). Nanocomposite samples were prepared by casting technique associated with incorporating 3 and 6 wt.% of TiB2 into matrix of Al-6wt.%Cu. Instron and wear tests machine were used to characterize the tensile and wear Al-Cu alloys properties. Results showed that increase in TiB2 content gave the high properties of tensile and wear behavior. The study indicates that TiB2 particles have giving improvement the wear performance of the Al–6wt.%Cu alloy. For a constant load and sliding speed, the wear rate decreases as a function of amount of TiB2 in the composite. The wear rate decrease with increasing in wt.% TiB2 particles for the all loads applied. However, addition of TiB2 particle to the Al–6 wt%. Cu matrix has show the coefficient value of wear decreases regardless of applied load. Study of the wear surfaces both alloy and composites by optical microscope suggests that the improvement in wear resistance is mainly due to the formation of finer groove or debris by content of TiB2

Mechanical properties of titanium-hydroxyapatite (Ti-HA) composite coating on stainless steel prepared by thermal spraying

Addition of hydroxyapatite (HA) can enhance the bioactivity of the common metallic implant due to its similarity with natural bones and teeth. In this investigation, high velocity oxy-fuel (HVOFT) technique was used to deposit titanium-hydroxyapatite (Ti-HA) composite on stainless steel substrate plate with different percentage of HA for biomedical applications. The aim of this research is to investigate the mechanical properties of Ti-HA coating such as hardness, adhesion strength and wear behaviour. The hardness and strength was determined by using SHIMADZU-microhardness Vickers tester and PosiTest AT portable adhesion tester respectively. The wear test was performed by using pin-on-disk equipment and field emission scanning electron microscope (FESEM) used to determine the extent of surface damage. From the results obtained, mechanical properties such as hardness and adhesion strength of titanium (Ti) coating decreased with the increased of HA contents. Meanwhile, the coefficient of friction of Ti-10% HA coating shows the highest value compare to others as three-body abrasion had occurred during the test

Preliminary study on properties of aluminium-silicon (Al-Si) alloys reinforced by in situ titanium diboride (TiB2)

Aluminum-silicon (Al-Si) alloys are an important class of materials, alloys which have great interested in wide industries whether in light or heavy industries, due to their superior properties like high strength to weight ratio, corrosion resistance, and excellent castability. The mechanical strength and the effect of modifying alloys have been studied. To evaluate the strength and revealed the structural of these alloys, the Instron tensile and Shimidzu Vickers hardness tester have been employed while the fracture surfaces have been observed by Scanning electron microscope (SEM). From results obtained, the microstructure of Al-Si with TiB 2 has much finer microstructure compared to unfine Al-Si alloy. It showed that the eutectic silicon microstructure in Al-Si alloy changed from needles-look or acicular to fine grain size or globular when the added of TiB 2 . The mechanical studies showed that the ductility of Al-Si alloy was much lower in the absence of grain refiner, TiB 2 . The tensile strength of unrefined Al-Si and Al-Si with 6 wt.%TiB 2 as grain refinement were recorded 275 and 312 MPa respectively. The hardness value for the unrefined Al-Si alloy also shows less compared with Al-Si with grain refiner, 6 wt.%TiB 2 , which are 74 and 78 MPa. This showed the results were significant improvements in mechanical properties have been obtained with the use of TiB 2 as grain refiner to Al-Si alloy

Characterization and mechanical properties of in-situ titanium diboride fibre reinforced aluminium-copper alloy composites

Aluminium (Al) based in-situ metal matrix composites (MMCs) have better properties and performance when compared to ex-situ MMCs. Al-MMCs alloys are quite attractive due to their low density, their capability to be strengthened by precipitation, their good corrosion resistance, high thermal and electrical conductivity. Aluminium-copper (Al-Cu) alloys is the one of most MMCs have important high-strength Al alloys. The Al casting alloys, based on the Al-Cu system are widely used in light-weight constructions and transport applications requiring a combination of high strength and ductility. Recently, in-situ techniques have been developed to fabricate Al-based MMCs, which can lead to better adhesion at the interface and hence better mechanical properties. These in-situ routes provide many advantages such as the in-situ formed reinforcement phases are thermodynamically stable, disperse more uniformly in matrix, free of surface contamination and leading to stronger particle matrix bonding.In this research, Al-Cu master alloy was reinforced with 1 to 6wt.% titanium diboride (TiB2) obtained from salts route reactions which were potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4) salts. The salts route reaction process done at 800 °C.. Then the Al-Cu alloy has characterized on the mechanical properties and microstructure characterization. The Instron tensile machine, Vickers and Rockwell hardness tester, and pin on-disc machine were used to characterize the tensile, hardness and wear properties of Al-Cu alloys respectively. Salts spray fog test and Gamry-electrode potentiometer were used to determine the corrosion rate of this alloys. From results obtained, the increasement of TiB2 contents will increased the value of tensile and hardness properties to Al-Cu alloy. The study also indicates that TiB2 particles have giving improvement the wear performance of the Al–6wt.%Cu alloy. For a constant load and sliding speed, the wear rate decreases as a function of amount of TiB2 in the composite. However, addition of TiB2 particle to the Al–6 wt%.Cu matrix has show the coefficient value of wear decreases regardless of applied load. Microstructure from scanning electron microscope (SEM) shows the composites synthesized using in-situ techniques exhibit the presence a uniform distribution of reinforcement that tends to be fine, and associated with a clean interface with the metallic matrix. Morphology observed that the particles of the TiB2 phase show a hexagonal morphology with straight and sharp edges. In order to achieve a good mechanical and wear properties it is important to control Al3Ti phase formation during the synthesis of in-situ Al-Cu/TiB2 composites. In corrosion test that conducted by salt spray fog and Gamry-electrode potentiometer, Al-Cu with composition of 3wt.%TiB2 gave the good properties in corrosion characterization compare to cast Al-Cu alloy itself. As comparison, Al-Cu with 3wt.%TiB2 gave the lowest value of corrosion rate, which means alloy has a good properties in corrosion characterization.The results obtained show that in-situ Al-Cu alloy composites containing different weight of TiB2 phase were synthesized successfully by the salt-metal reaction method and the particles were distributed evenly in the matrix of the composites

Kinetic Study of Natural Anticancer Drug (Zerumbone) Release from Zeolite Y-Gelatin Hybrid for Oral Controlled Delivery

A hybrid of zeolite Y-gelatin film as an oral dosage form for the natural anticancer drug was achieved by homogenously incorporating the drug-loaded zeolite Y into the gelatin solution. Drug ability was analyzed using computational and experimental approaches, drug encapsulation efficiency via the BET method, and possible interactions by FTIR analyses. Zerumbone released was done in both pH 1.2 and pH 7.4 mimicking the human gastrointestinal tract conditions for 24 hrs and subjected to kinetics study via suitable mathematical models to determine what governs the drug release with the results indicating that a sustained delivery of once-daily oral dosage form could be achieved

Corrosion characterisation of Al-Cu reinforced in-situ TiB2

Aluminium (Al) based in-situ metal matrix composites (MMCs) have better properties and performance compared to ex-situ MMCs. In this research, aluminium-copper (Al-Cu) alloy was reinforced with 3 and 6wt.% titanium diboride (TiB2). Al-MMCs has been fabricated with salt route reaction process at 800 °C via potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4) salts. Hardness vickers tester and Gamry-Electrod Potentiometer were used to characterize the hardness properties and to determine the corrosion rate of Al-Cu alloys. From results obtained, increased TiB2 contents will increase the hardness of Al-Cu alloys. Increased of TiB2 contents also will increase the corrosion rate of Al-Cu alloys. Al-Cu with 3wt.%TiB2 gave the good properties of corrosion when the wear rate recorded the lowest value compare to Al-Cu alloy itself and 6 wt.% TiB2. The corrosion rate of Al-Cu with 3wt.TiB2 was 16.15, while Al-Cu and Al-Cu-6wt%TiB2 were 22.5 and 58.7 mm/y respectively

Advocating electrically conductive scaffolds with low immunogenicity for biomedical applications: A review

Scaffolds support and promote the formation of new functional tissues through cellular interactions with living cells. Various types of scaffolds have found their way into biomedical science, particularly in tissue engineering. Scaffolds with a superior tissue regenerative capacity must be biocompatible and biodegradable, and must possess excellent functionality and bioactivity. The different polymers that are used in fabricating scaffolds can influence these parameters. Polysaccharide-based polymers, such as collagen and chitosan, exhibit exceptional biocompatibility and biodegradability, while the degradability of synthetic polymers can be improved using chemical modifications. However, these modifications require multiple steps of chemical reactions to be carried out, which could potentially compromise the end product?s biosafety. At present, conducting polymers, such as poly(3,4-ethylenedioxythiophene) poly(4-styrenesulfonate) (PEDOT: PSS), poly-aniline, and polypyrrole, are often incorporated into matrix scaffolds to produce electrically conductive scaffold composites. However, this will reduce the biodegradability rate of scaffolds and, therefore, agitate their biocompatibility. This article discusses the current trends in fabricating electrically conductive scaffolds, and provides some insight regarding how their immunogenicity performance can be interlinked with their physical and biodegradability properties.This work was carried by the NPRP grant # NPRP11S-1221-170116 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The authors wish to thank Norzawani Buang M Yassin, of Imperial College London, United Kingdom, for the useful discussion.Scopu

Synthesis and Characterization of Porous, Electro-Conductive Chitosan–Gelatin–Agar-Based PEDOT: PSS Scaffolds for Potential Use in Tissue Engineering

Herein we report the synthesis and characterization of electro-conductive chitosan–gelatin–agar (Cs-Gel-Agar) based PEDOT: PSS hydrogels for tissue engineering. Cs-Gel-Agar porous hydrogels with 0–2.0% (v/v) PEDOT: PSS were fabricated using a thermal reverse casting method where low melting agarose served as the pore template. Sample characterizations were performed by means of scanning electron microscopy (SEM), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), X-ray diffraction analysis (XRD) and electrochemical impedance spectroscopy (EIS). Our results showed enhanced electrical conductivity of the cs-gel-agar hydrogels when mixed with DMSO-doped PEDOT: PSS wherein the optimum mixing ratio was observed at 1% (v/v) with a conductivity value of 3.35 × 10−4 S cm−1. However, increasing the PEDOT: PSS content up to 1.5 % (v/v) resulted in reduced conductivity to 3.28 × 10−4 S cm−1. We conducted in vitro stability tests on the porous hydrogels using phosphate-buffered saline (PBS) solution and investigated the hydrogels’ performances through physical observations and ATR–FTIR characterization. The present study provides promising preliminary data on the potential use of Cs-Gel-Agar-based PEDOT: PSS hydrogel for tissue engineering, and these, hence, warrant further investigation to assess their capability as biocompatible scaffolds