Key Engineering Materials Vol. 877

Abstract: The effect of compatibilizer agent was studied when adding Aluminum fine powder (Al) to reinforce in Polypropylene (PP) by compared between polymer matrix composites (PMCs) and PMCs added Polypropylene graft maleic anhydride (PP-g-MAH).The average particle size of the aluminum fine powder was around 75 μm filled in polypropylene with different proportions of 2.5, 5, 7.5 and 10wt%. PMCs were prepared using the internal mixer. The results found that when the amount of aluminum fine powder increased, the mechanical properties had changed, i.e., tensile strength, and Young’s Modulus increased, while the impact strength and elongation at break decreased. But, when adding compatibilizer 1wt% it was found that the trend of tensile strength, and Young’s Modulus increased that compared with non-compatibilizer, but the impact strength and elongation at break decreased. The part of the morphology of PMCs with non-compatibilizer was found that the particle of aluminum fine powder dispersed in the matrix phase, but there were many microvoids between filler and matrix. But, PMCs with compatibilizer caused the microvoids between filler and matrix to be reduced.

Abstract: Iron oxides and similar inorganic compounds have served as anti-corrosion fillers for metal coatings. Environmental issues related to the mining of metallic fillers have stimulated interest in alternative fillers such as organic fillers. This paper explores the use of comminuted waste plastic sachets (WPS) as an anti-corrosion filler to resin-based metal coating. Mixture design of experiment was used to study the effect of iron oxide-WPS blends on the film thickness, viscosity, corrosion behavior, and water resistance of the coating. Results show that the film thickness was affected by the presence of iron oxide while the viscosity of the coating was affected by high loads of WPS. Among all coatings, the blend containing 25% iron oxide and 75% WPS produced the highest corrosion resistance. In conclusion, comminuted WPS provided additional corrosion resistance and could serve as an alternative anti-corrosion filler.

Abstract: In this study, we modified polypropylene (PP) by using melt-blending hollow silica (HSiO₂) with it and to form HSiO₂/PP composites. The composites were characterized by mechanical properties, X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FTIR). In order to investigate the effect of nanofiller to the barrier property of water vapor, the water vapor transmission rate of PP and HSiO₂/PP composites has been tested. The study found that the addition of HSiO₂ did not change the crystal structure of the matrix material and there was no chemical reaction. However, the tensile strength of the composite is improved, and the water vapor barrier performance were also improved. When the content of HSiO₂ is 0.9%, the tensile strength of the composite is the highest and the water vapor resistance is the best.

Abstract: Biodegradable composite from polycaprolactone (PCL) and Graphene/zinc oxide (Graphene/ZnO) is studied. The Graphene/ZnO content is at 0.5%, 1.5% in PCL. Neat PCL and composites were characterized by microstructure, mechanical properties and thermal properties. Scanning electron micrographs show that the additive has agglomerated in PCL/Graphene/ZnO. Agglomeration of the filler results in reduced tensile properties of the composite. The result from XRD indicates Graphene/ZnO can improve the crystallinity of PCL. According to the results of buried soil test and analysis, Graphene/ZnO can reduce the biodegradation rate of PCL and make the material more durable. This new biodegradable composite material can be used as a new environmentally friendly material.

Abstract: A solution blending technique was employed to form a nanocomposite film of polyvinyl alcohol modified with carbon nanotube and zinc oxide (CNT/ZnO). The film was characterized using a tensile testing machine, X-ray diffraction, scanning electron microscopy, a contact angle device, and barrier property measurement. When the CNT/ZnO content was 1.2 phr, the results from mechanical property and water vapor permeation tests showed that the nanocomposite film had good tensile strength and water resistance. Moreover, CNT/ZnO improved the hydrophobicity of the film. CNT/ZnO/can improve the performance of PVA and is a good nanofiller of PVA. The results of this research might have the opportunity to be used as packaging film materials in the future.

Abstract: The effect of modified silica fume (mSF) and cellulose fiber (CF) content on the cure characteristics, mooney viscosity, mechanical, durability and heat resistance properties are investigated; as compared with SF and unfilled natural rubber. From the results reveal that mSF and CF affect not only fast cure rate, high viscosity but also improve rubber mechanical and heat resistance properties. Additionally, the mSF and CF are added into the natural rubber to produce antivibration rubber product and then study the rubber product performance such as durability properties. The mSF and CF effective in improving the crack resistance of antivibration rubber product more than SF and unfilled natural rubber which is due to enhancing the stiffness. The all obtained results, it can be proved that mSF and CF as the new alternative fillers in rubber industry.

Abstract: Bacterial cellulose (BC) is high purity and several current potential uses in industries. Liquid byproduct of sweet corn canning process (SC) contains fermentable sugars which could be utilized to get higher economic benefits. Therefore, this research aimed to produce BC from SC by Gluconacetobacter xylinus under static condition and use it to improve mechanical properties of natural rubber. The ratio of SC to coconut juice for cellulose production was studied. The result revealed that production yield, water holding capacity and tensile strength of BC produced from the medium containing coconut juice to SC at a ratio of 75:25 (w/w) supplemented with 1% acetic acid, 1% ammonium sulfate and 5% sucrose (w/w) was not significant different from BC obtained from a coconut juice medium. The FTIR spectra of BC showed the characteristics of cellulose. The morphology of BC exhibited high fibril network. BC is showed reinforcement in natural rubber composites due to enhance the stress value, whereas reduce the strain value.

Abstract: On the one hand, many mechanical components manufactured through additive technologies are optimized in terms of stiffness/weight or strength/weight thanks to lattice structures. On the other hand, the high complexity of these components often impedes further finishing operations and, therefore, the fatigue strength can be compromised. The high surface to volume ratio together with the high roughness, typical of additive manufactured components, promote the crack nucleation. In this paper, the High-Cycle-Fatigue (HCF) behavior of the 17-4 PH stainless steel (SS) was characterized. Cylindrical samples, manufactured via Selective Laser Melting (SLM) with an EOS M280, were tested in the as-build condition through a STEPLab UD04 fatigue-testing machine. In particular, a preliminary quasi-static traction test was performed on a sample to obtain the yield strength (σ_Y = 570 MPa) and the ultimate tensile strength (UTS = 1027 MPa). Fatigue tests were performed on samples at different stress levels in order to characterize the whole Stress-Number of cycles (S-N) curve (Wöhler diagram). More specifically, the stair-case method combined with the Dixon approach were exploited to calculate the fatigue limit (σ_F = 271 MPa). The obtained results were compared with those present in literature for the same material and they are coherent with previous researches

Abstract: In this paper, the static and low-cycle-fatigue (LCF) behavior of wrought samples of 17-4 PH stainless steel (SS) manufactured via Selective Laser Melting (SLM) are presented. On the one hand, several scholars have studied SLM materials and literature reports a huge amount of data as for the high-cycle-fatigue (HCF) behavior. On the other hand, few are the data available on the LCF behavior of those materials. The aim of the present research is to provide reliable data for an as-build 17-4 PH steel manufactured via SLM techniques. Only with quantitative data, indeed, it is possible to exploit all the advantages that this technology can offer. In this regard, both quasi-static (QS) and low-cycle-fatigue tests were performed on Additive Manufacturing (AM) cylindrical samples. Through QS tests, the constitutive low has been defined. Strain-controlled fatigue tests on an electromechanical machine were performed on 12 samples designed according to the ASTM standard. Tests were continued also after the stabilization was reached (needed for the cyclic curve described with the Ramberg-Osgood equation) to obtain also the fatigue (ε-N) curve. Results show that the material has a softening behavior. The Basquin-Coffin-Manson (BCM) parameters were tuned on the basis of the ε-N combinations after rupture.