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This study proposes of harmonizing the original approach of aluminium alloy recycling through hot press forging. By eradicating the melting phase, most of the waste generation can be significantly reduced. To cope with the technology revolution, the finite element is utilised to predict the material behaviour without practically executing the trial. By employing three-dimensional finite element analysis through DEFORM 3D, the evaluations were demonstrated by simulating the isothermal forging process. The flow stress of the material was modified to adequate with the aluminium-based metal matrix composite used in the actual experiment. To that extent, this study found out that the strain of the workpiece had gradually increased on each step. A reduction of ~10% of the flesh observed in the simulation is roughly the same as existed on the experiment workpiece. Above all, the simulation conducted abides by the standard and follows the actual practice that has been done previously. Through the finite element utilization, this study discussed the performance of the recycled based composite. The result presented here may facilitate improvement in the recycling issue and also conserved the environment for the better future.

This paper aims to predict the hardness of hot formed part for tailor rolled blank (TRB) by the FE-simulation coupled with quenching factor analysis (QFA). Dilatometry test of boron steel is performed at various range of cooling rates from 0.2 to 100°C/s using the dilatometer with forced air cooling system. The dilatometry test provides a hardness data according to cooling curves which are used to determine the material constants (K1~K5) of QFA and the time‒temperature‒property (TTP) diagram of boron steel. Then, FE‒simulation of hot press forming is conducted to predict the cooling curves of hot formed TRB part with a thickness combination of thicker 1.6mm and thinner 1.2mm which is called as rear side member of automotive component. The cooling curves of FE-simulation are applied to predict the hardness of hot formed rear side member using the QFA. Also, experiment of hot press forming is performed to verify the predicted results and to examine the effect of cooling curves on the hardness.

TiCN-based cermets were prepared by hot-press sintering through adding various amounts of AlN nanopowder (0-20 wt.%) into a 64 wt.% TiC0.5N0.5-10 wt.% WC-8.5 wt.% Mo-12.5 wt.% Ni-5 wt.% Co system. The microstructure and mechanical properties of the prepared cermets were investigated. For the prepared cermets, samples with 5 wt.% AlN nanopowder exhibited optimum mechanical properties of Vickers hardness 2191 HV10, bending strength 601 MPa, and fracture toughness 6.03 MPa.m1/2, respectively.

Tungsten carbide (WC) targets with low cobalt (Co) content (0.1 - 0.2 wt.%) were prepared by hot-press sintering at 1700°C for 60 minutes in argon, from element starting powders of tungsten, cobalt and carbon. Results show that the as-fabricated targets yield relatively high relative density above 99% and high HRA above 92. WC with low Co content is formed easily than pure WC. The hot-press sintering process, while element starting powders are used, is an in-situ reaction technique for accelerating the WC’s diffusion rate to obtain a dense sintered body.

B4C and ZrB2 ceramic tapes were prepared by non-aqueous tape casting with B4C and ZrB2 as main materials, xylene and n-butanol as binary solvent, castor oil as dispersant, polyvinyl butyral (PVB) as binder and dioctyl phthalate (DOP) as plasticizer. B4C-ZrB2 laminated composites were prepared by cutting, laminating, dumping and hot-press sintering. The experiment results indicated that ZrB2 ceramic tapes with high solid content of 48 wt.% could be prepared with 0.8 wt.% castor oil, 3.4 wt.% PVB and 6.8 wt.% DOP. Ceramic tapes have smooth surface, no crack and good ductility. B4C-ZrB2 laminated composites with high relative density of 97.8% were prepared by hot-press sintering under 2020°C sintering temperature, 30MPa pressure, 35 min hold temperature and pressure time. Their bending strength and fracture toughness were 488.6 MPa and 5.85 MPa·m1/2 respectively.

In this research, the W-40wt.%Cu composite tape-casting films were prepared through the vacuum hot-press sintering method, and the effect of sintering temperature on the microstructures and properties of the W-40wt.%Cu composite samples was studied. Microstructures of the W-40wt.%Cu tape-casting film and the prepared samples were analyzed by field emission scanning electron microscopy (FE-SEM). The phase of the samples was investigated by X-ray diffraction (XRD). The relative density, Vickers hardness, bending strength and electrical conductivity of the samples were investigated. The results show that the relative density of the W-40wt.%Cu composite materials enhances with the increasing of the sintering temperature, at the same time the mechanical and electrical properties are better with the increasing of the sintering temperature. The W-40wt.%Cu composites prepared at the condition of 900°C-200MPa-2h have the relative density of 97%, the bending strength of 507.3MPa, the Vickers hardness of 376.2HV and the electrical conductivity of 32.5% IACS, respectively.

Layered ternary compounds Ti3SiC2combines attractive properties of both ceramics and metals, and has been suggested for potential engineering applications. Near-fully dense Ti3SiC2bulks were sintered from commercial Ti3SiC2powders by hot press at 1350°C-1600°C for 60-120min under Ar atmosphere in this paper. The phase compositions and morphology of the as-prepared samples were evaluated by X-Ray diffraction (XRD) and scanning electron microscopy (SEM). And the mechanical properties were measured by Three-Point bending method. It was found that the Ti3SiC2had only a little of decomposition at sintering temperature above 1350°C. And effects of sintering temperature and holding time on the morphology of the bulk Ti3SiC2are not obvious. Relative density of 98% and flexural strength of 480MPa were obtained for the Ti3SiC2samples sintered at 30MPa and 1400°C for 90min.

The hot press moldability of bamboo powder without additives was investigated in this study. Bamboo powder was hot pressed into self-bonded cylindrical moldings at temperatures of 160 to 200 oC and pressing times of 1 to 20 min at a punch surface pressure of 200 MPa. After pressing, the color, density and bending properties of the moldings were evaluated. The bending strength, bending elastic modulus and density were found to increase with an increase in temperature, and moldings having good mechanical properties were obtained at a temperature of 200 oC. With respect to the influence of hot pressing time on moldability, a maximum bending strength of 34 MPa was achieved for a time of 10 min at a temperature of 200 oC. In addition, we removed moldings from the mold after cooling to 100 oC or less in order to improve the surface texture and density of the moldings. The results showed a cooled molding had a good surface texture (resembling plastic) and a bending strength of 53 MPa.

SiC-TiB2/B4C composites were fabricated by hot-press sintering B4C with silicon powder and tetrabutyl titanate (precursor of TiO2) as sintering and reinforcement agents. The influence of additives on hot-press sintering densification, microstructure and properties of composites were studied. The results showed that TiB2 and SiC generated by chemical reaction between additives and B4C matrix reinforced the sintering activity of the mixed powders and accelerated significantly the hot-press sintering densification rate of B4C from 1200 °C to 1700 °C. According to the SEM observation, the second phase of TiB2 and SiC particles synthetized in situ sited along the grain boundaries of B4C, meanwhile, those SiC particles of nanoscale size embedded into the B4C grains, and thereby, intra/inter-type ceramics formed. The maximum relative density of 98.1% was obtained with 9wt.% TiO2. The typical valus of Vickers hardness, bending strength and fracture toughness can reach 26.7 GPa, 580 MPa and 5.0 MPam1/2, respectively.

PLMNT3/75/25 ceramics were prepared by uniaxial hot-press sintering method and conventional sintering method, respectively. X-ray diffraction (XRD), scanning electron microscopy (SEM) and impedance analyzer were used to measure the properties of the PLMNT ceramics. PLMNT ceramic with pure perovskite phase was fabricated by uniaxial hot-press sintering method, while, a secondary pyrochlore phase was found in PLMNT ceramic prepared by conventional sintering method. It was observed that the PLMNT ceramic fabricated by uniaxial hot-press sintering showed better densification and more uniform grain size than that of the PLMNT ceramic prepared by conventional sintering. The dielectric responses showed that the samples prepared by two methods both exhibited diffuse phase transition characteristic, and the values of the diffusivity parameter were calculated according to the linear fitting of the modified Curie-Weiss law. The relaxor ferroelectric characteristics of PLMNT ceramics accorded well with the Vogel-Fulcher relationship. The P-E hysteresis loops of the samples from uniaxial hot-press sintering were apparently slight than that of conventional sintering samples, while the value of the Ps (saturation polarization) was significantly higher.

In the present study, coating of some magnesium alloys including AZ31 and AZ91 were studied using different techniques namely anodizing, electroless and hot press cladding. AZ91 alloy was coated using anodizing process using three types of environmental friendly electrolytes; the first based on sodium silicate, the second based on sodium hydroxide-boric acid-borax and the third on sodium silicate-potassium hydroxide-sodium carbonate-sodium tetra borate. Characterization of the anodizing layer was achieved by determination of surface morphology, microstructure, phase analysis, coat thickness, adhesion and corrosion resistance. It was found that the anodic film thickness increases with increasing the current density, anodizing voltage and deposition time until the deposition stops due to the formation of a thick anodic film. The range of the anodic film thickness is 28 42 µm.Optimization of the anodizing conditions - current density and deposition time was determined for each electrolyte. A corrosion efficiency ranging from 94% to 97% was reached; the highest value corresponding to the third electrolyte. Another study is the electroless Ni plating technique with zinc pre-treatment applied on several magnesium alloys and the effect of pre-treatment and post heat treatment on the coat characteristics. The surface morphology, surface roughness, thickness of the layer, EDX analysis, adhesion, hardness and corrosion resistance are covered in this part. The electroless layer thickness is about 6 µm. The results showed good bond quality of the coat maintaining good corrosion behaviour of electroless Ni-P based on potentiodynamic polarization tests in chloride solution where it was improved after heat treatment process. On the other hand, AZ31 was covered by a commercial pure aluminum sheet by hot pressing. The influence of the applied pressure, holding time and temperature on the bond characteristics was studied. The experimental investigation has revealed a good bond quality due to the effective mutual diffusion of Mg and Al. The phase analysis resulted in the formation of two equilibrium phases namely; Mg17Al12and Mg2Al3. The corrosion resistance of AZ31 is enhanced as a results of this process by 98.6%. Further points will be covered.Keywords: Magnesium alloys; Coating; Anodizing; Electroless; Hot press cladding; environmental friendly electrolytes; corrosion

High performance composites are used in commercial applications in a steadily growing degree. This increase of advanced materials is accomponied with the development of fully automated fabrication processes. It aims to drive down the time and costs of the production while ensuring a high quality of the product. This can achieved by considering the process of hot press forming with continuous fiber reinforced thermoplastics. The development of the process is, however, accompanied with a few difficulties, which require more research. For example, composite materials with different architectures, lay-ups, and constituents, show large differences in formability. This research examines the effect of friction on the formability of thermoplastic composites. Both experiments and simulations were conducted. Demonstrator products have been press-formed from laminates with different materials and architectures (UD-carbon PEEK, UD-carbon-PEI, 8hs-glass PPS, 5hs-carbon PEEK and UD-glass PPS), to investigate their effects on formability. Creating a doubly curved shape from a flat laminate requires at least three deformation mechanisms, namely in-plane shear, bending and inter-ply slippage This paper focuses on the sliding mechanism and the corresponding friction. In order to quantify the amount of sliding in the press-formed product, a dot pattern has been applied to both surfaces of the laminate. The slip between the outer plies can be analyzed by means of photogrammetry. Besides, the friction coefficient of each material is measured in a special designed friction test set-up. It can be seen that the composite formability is directly linked to its friction properties. FE simulations of the press-form process will be performed based on the measured material properties, to demonstrate the influence of the materials friction coefficient.

Sodium superionic conductor, NASICON ceramic (Na1+xZr2SixP3-xO12, x=2), was hot-press sintered under different temperatures and the electrical properties of the obtained different samples were investigated. Results show that the relative density of the ceramics can be improved by hot-press process efficiently and the crystal size of the samples are closely related to sintering temperature. With the increase of sintering temperature, both the density and the crystal size of samples increase obviously, resulting in the increase of ionic conductivity of samples as the sintering temperature. When the sintering temperature reaches 1150oC, the ionic conductivity of sample is as high is 3.6×10-3S/cm, which is obviously higher than that of sample sintered at 1000oC (2.13×10-3S/cm). As the frequency increase, the real parts and the imaginary parts of complex dielectric constants for all the samples decrease in 8.2 GHz~12.4GHz frequency band. The ceramics obtained at the higher temperature possess the higher dielectric constant.

Two types of press hardening experiments were carried out to investigate the behavior of ZnFe coated 22MnB5 steel in direct press hardening process. The coating properties were studied using variable process temperatures and times with a flat-die and a forming tool. Coatings were analyzed with optical and scanning electron microscopes. The results indicated that steels that have low coating weights may be processed successfully with short dwell times. For high coating weights a significantly longer dwell time is needed. The behavior of ZnFe coating in hot press forming experiments was in line with literature and the findings of the flat-die experiments. Thus, the feasibility of the experimental press hardening equipment was confirmed.

In this study, effect of crystallinity on mechanical properties of carbon fiber reinforced thermoplastics (CFRTP) was investigated. Polypropylene (PP) and maleic anhydride modified polypropylene (MAPP) were used as matrix. The crystallinity of PP was controlled by using heat treatment after hot press molding of CFRTP. The range of crystallinity of PP and MAPP were from 26% to 40%. Flexural tests and izod impact tests of CFRTP were conducted based on Japanese Industrial Standard (JIS) K 7074 and JIS K 7110, respectively. As a result, flexural property and izod impact value of CFRTP using PP increased with an increase of crystallinity. However, flexural property and izod impact value of CFRTP using MAPP almost did not change with an increase of crystallinity.

This study dealt with the characterization of MoSi2 based composites containing three types of additive materials such as SiC, NbSi2 and ZrO2 particles have been investigated, based on the detailed examination of their microstructures and fracture surfaces. The effects of reinforcing materials on the high temperature strength of MoSi2 based composites have been also examined. MoSi2 based composites were fabricated by the hot press process under the vacuum atmosphere. The volume fraction of reinforcing materials in the composite system was fixed as 20 %. The microstructures and the mechanical properties of MoSi2 based composites were investigated by means of SEM, EDS, XRD and three point bending test.

Titanium aluminide composite reinforced with submicron Al2O3 has been prepared by a reactive hot press method using TiO2, Al and Ti powder as source materials. The reaction synthesis processing is particularly investigated. Results show that the matrix of the as-prepared material is a mixture of TiAl and a small amount of Ti3Al. Fine Al2O3 particles that act as reinforcing phase are dispersed along the interface of the matrix. The reduction of TiO2 involves many transitional stages, including Ti-Al reaction, TiO2-Ti reducing reaction, reaction between TiO2 and Al, etc.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we propose a sustainable manufacturing system using bamboo. A method is also proposed for extracting bamboo fibers end-milled using a machining center with in-situ measurement. Bamboo fibers with highly precise shapes are efficiently acquired. Previously, we proposed the fabrication of a binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, we have not yet constructed a method to obtain the best fiber extracting and molding conditions considering both its efficiency and performance. Therefore, in this report, we investigate the influence of the length of used bamboo fiber on the characteristics of the molded products, as its length deeply affects the extracting efficiency and focuses on a degradable plastic as a standard of molded product strength.

Bamboo grows faster than other renewable natural materials. Bamboo fibre, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibres end-milled using a machining centre with in-situ measurement was also proposed. Bamboo fibres with high precision shapes are efficiently acquired. Previously, we proposed the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibres extracted by a machining centre. We experimentally demonstrated various hot press forming conditions and achieved proper ones to optimize the forming process. However, when the environment changes, the characteristics of the binder-free composite are not known. If we want to use the binder-free composite, we have to know how much it is affected by the external environment for use as a mechanical object. Therefore, we investigated the changes of the characteristics at high temperature and high humidity.

Three types of polycrystalline alumina, one pressureless and two hot press sintered Al2O3, were used to examine the effects of the characteristics of microstructure and crack face bridging on fracture toughness. The crack opening displacements and microstructures along the pop-in crack of single edge precracked beam (SEPB) specimens were observed in situ at a constant applied stress intensity factor by scanning electron microscopy (SEM). The bridging stress distribution could be determined from the measured crack opening displacement by three-dimensional finite element analysis, and then the stress intensity factor and stress shielding effect at the crack tip could also be determined. Intergranular microcracks of toughened Al2O3 were deflected by a complicated microstructure, and crack closure due to bridging grains was observed near the crack tip. Bridging stress of Al2O3 was compressive perpendicular to the crack face and was distributed behind the crack tip. The maximum bridging stress of two hot press sintered Al2O3 was about twice as large as that of pressureless sintered Al2O3. The fracture toughness of hot press sintered Al2O3 was, therefore, higher than that of pressureless sintered Al2O3, because the total amount of bridging stress and stress shielding effect increased with increasing magnitude of microcrack deflection and the number of interlocking grains.

Bamboo grows faster than other renewable natural materials. Bamboo fiber, in particular, has attracted attention as an environmentally superior material. Therefore, we proposed a sustainable manufacturing system using bamboo. An extraction method of bamboo fibers end-milled using a machining center with in-situ measurement is proposed. Bamboo fibers with high precision shape are efficiently acquired. In the present report, we propose the fabrication of binder-free composite by a hot press forming method that only uses bamboo fibers extracted by a machining center. We experimentally demonstrated various hot press forming conditions and achieved proper forming conditions to optimize the forming process. We also made various three-dimensional shapes considering the practical applications of the formed binder-free bamboo fiber moldings.

In order to investigate the effect of hot-press fabrication parameters on mechanical properties of Al2O3 ceramic tool materials, the orthogonal experiment method was used. In the experiments, the three influence factors such as the fabrication temperature, pressure and duration time are considered. The experimental results are analyzed by a range analysis of orthogonal experiments. It is shown that the most important factor that affects the mechanical properties is the fabrication temperature and the followed factors are the fabrication pressure and the duration time of fabrication. Scanning electron microscope (SEM) reveals that the hot-press fabrication parameters will significantly affect the microstructure of ceramic tool materials, which can govern the mechanical properties. This has been validated by the orthogonal experiments in the present paper.

In this paper, silicon nitride (Si3N4) ceramics by aligning α-Si3N4 whiskers were prepared via tape casting, hot-press sintering technique using Y2O3 and MgO as sintering additives. Aligned α-Si3N4 whiskers were realized by modifying the tape casting technique. After tape casting, Si3N4 tape with good flexibility and uniform pores can be obtained. Microstructures of the tape, green body and sintered sample were observed by SEM images. The results show α-Si3N4 whiskers in Si3N4 tape and green body were aligned preferentially along the tape casting direction. Si3N4 ceramics with aligned elongated grains are developed by hot-press sintering technique based on the reaction between Si3N4 and the sintering additives which lead to the liquid phase.

Hydroxyapatite is a kind of ideal biomaterials for bone and teeth replacement, but its low strength and brittleness need to improve. As bone replacing materials, hydroxyapatite (HAP) and zirconia both have advantage and disadvantage. Nano-sized HAP-ZrO2 powders and HAP-TZP (3Y) (3mol% yttria - stabilized cubic zirconia) bioceramic for artificial joint have been fabricated in this paper. The nano-sized HAP-ZrO2 powders with homogeneous distribution could be synthesized by two-step precipitation method. The HAP-TZP bioceramic with small grain size could be obtained by using hot-press sintering technology, and the sintering parameters are: sintering temperatures T=1300°C, sintering pressure p=30MPa and sintering time t=30min. The mechanical properties, microstructures and fracture pattern that were analyzed by SEM and optical microscopy of the HAP-TZP bioceramic were investigated systematically. The results show that no reaction between HAP and ZrO2 powders, which could be attributed to the very short sintering time of hot press sintering.

Effects of different sintering methods such as pressureless sintering and hot press sintering on relative density and microstructure of the Al2O3p/LiTaO3 (ALT) composite ceramics were investigated to obtain a preferable sintering process. Relative densities of all ALT composites are below 90% when sintered with the cold isostatical pressing followed by pressureless sintering at temperatures of 1250 to 1350°C. The relative densities and microstructure of ALT composite ceramics with the hot press sintering process in a N2 atmosphere at 1150 and 1300°C were investigated. The relative density of ALT composite hot pressed at 1150°C is only 77%, and almost theoretical density at 1300°C. This indicates that sintering pressure plays an important role in the densification of ALT composite ceramics in temperature range of 1150 to 1350°C. Investigation on morphologies of the composites shows that the Al2O3 particles distributed along grain boundaries of LiTaO3, which leads to a fine-grained microstructure in the ALT composite ceramics

Polypropylene resins have been enfolded with the automotive industry and suppliers to produce several spare parts. This is aimed at achieving zero emissions, kenaf plant which in Latin is Hibiscus Cannabinus is a natural fiber replacement resin. Natural fiber composites come in many different types, but kenaf has been exploited extensively over the last few years. The pre-board flow process of kenaf-polypropylene starts from mixing kenaf about 40% with 60% polypropylene, forming a pre-mat as the first output, entering the main treatment with the hot press into pre-board as the final output. Kenaf-polypropylene door trim is very absorbent of CO2, which is related to natural fiber base material. Door trim with kenaf-polypropylene as the base material reduces the weight by about 30% of the previous polypropylene resin and still provides high rigidity even at a reduced weight. The entire process is requiring 48382.4 kWh / month per cycle of total power consumption.

Recently, natural fiber reinforced polymer composites have become popular over traditional synthetic fiber reinforced polymer composites for automotive, low demanding structural and semi-structural applications. In this work, a comparative study of a natural fiber composite such as jute fabric composite (JFRP) and synthetic fiber composite such as glass fiber composite (GFRP) is presented. The composites were manufactured using hand lay-up and then curing at 90°C for 10 min in a hot press, followed by 24 h room temperature post-curing. The mechanical properties such as tensile and bending of JFRP and GFRP composites, were evaluated and compared. It was revealed that even if GFRPs exhibited significantly higher mechanical properties than JFRPs, environmental impact would still favor JFRPs for non-structural and low load bearing applications.

The main objective of this investigation is to reduce and eventually replace the use of non-biodegradable synthetic fiber. Bio composites have shown growth and has been used in the domestic sector, aerospace industry, circuit boards, and automotive applications over the past few years. Many types of natural fibres have been investigated to produce composite materials that are competitive with synthetic fibre composites. Jute is a natural fibre and is 100% bio-degradable and recyclable and thus environmentally friendly. Its properties include high tensile strength, low extensibility. This bio composite specimen has been fabricated with the help of hot press molding machine. The flexural and Tensile tests have been done according to the ASTM standards. The increasing awareness of global environmental and social concern and new environmental regulations have propelled the search for new composites that are compatible with the environment.

An effective integration of natural fibers into engineering thermoplastics requires sufficient thermal stability of natural fibers during processing, since melting temperature of engineering thermoplastics lies above 200 °C. The aim of the work was to protect natural fibers from the heat of the molten thermoplastic via coating with a modified epoxy resin, thus enabling manufacture of natural fiber-reinforced engineering thermoplastic composites with minimized thermal degradation of the fibers. Processing temperature comprised the range of engineering thermoplastic polyamide 6 (PA6), which was 225 °C. Flax fabrics were spray coated with partially bio-based epoxy resin and incorporated via hot press technique into a PA6 matrix. The composite samples including spray coated flax fibers as well as the reference flax fibers without coating were characterized with regard to their mechanical properties, namely bending and tensile tests, thermal properties with differential scanning calorimetry (DSC) as well as thermogravimetric analysis (TGA) and optical via scanning electron microscopy (SEM) and computer tomography (CT). The results show that this approach enables manufacture of composites with reproducible mechanical properties, i.e. bending and tensile properties as well as enhanced thermal stabilities.

Development of environment-friendly materials to improve the safety and fuel efficiency of automobiles has attracted great research attention with regards to the automobile industry in recent years. With increase in demand for technological developments to improve performance and efficiency, an increased number of researches are being performed concerning the use of advanced high-strength steel in parts manufactured by means of the hot-press forming process. Furthermore, research concerning the improvement in fuel efficiency through additional weight reduction using tailor-welded blanks (TWBs) and partial quenching (PQ) has gained popularity in the automobile industry in recent times. Many car components are, nowadays, being fabricated using different materials to improve collision toughness and safety in the event of a car crash. However, no standard has yet been established to evaluate the replacement of automobile parts, and such a standard must account for mechanical properties of the material under tensile and flexural loadings. A car crash test was conducted at the Insurance Institute for Highway Safety (IIHS) to evaluate automobile safety. However, collision-toughness evaluation of each car component is expensive and difficult to realize. In this study, drop tests were simulated, and collision characteristics of the center-pillar were correspondingly evaluated. Values of fracture toughness were compared in accordance with center-pillar types for evaluating collision-test conditions.

This research focuses on the mechanical and morphological properties of acacia wood (AW) reinforced polyhydroxyalkanoates (PHA) bio-composites. Acacia woods waste in the form of sawdust was processed into short wood fiber, which was later mixed with pure PHA with different fiber loading (5wt%, 10wt%, 15wt% and 20wt%). The acacia wood fibers were chemically modified by using the naturalization technique (which used both acidic and alkaline base) using acetic acid and sodium bicarbonate. The hot press machine was used to fabricate the samples. Tensile and flexural samples were fabricated and tested according to the ASTM standards. The SEM images show that the chemically modified acacia wood reinforced PHA (M-AW-PHA) bio-composites create desirable adhesion which contributed to better mechanical strength at 15wt%, when compared with untreated acacia wood reinforced PHA (U-AW-PHA) bio-composites.

The effect of a silane coupling on curing characteristics, mechanical properties, abrasion behavior and swelling behavior of waste silicon carbide filled natural rubber compounds was investigated in the concentration 3%, 6%, 9%, 12% and 15% by weight of the particles. The waste silicon carbide content in this study was fixed at 30 phr in order to reveal the influence of silane-69 used to modify silicon carbide. The rubber compounds were prepared using a laboratory two roll mill with temperature maintained at 50°C. The curing characteristics of the composites were determined and the composites were vulcanized at 160°C using a hot press. The properties of the natural rubber compounds such as modulus at 200% elongation, stress at peak, hardness, abrasion resistance and swelling behavior were studied. Results indicate that the maximum torque of the natural rubber compounds increased with increasing silane-69 content whereas the silane-69 can be used without much effect on the scorch time and cure time. Increasing silane-69 content also gives natural rubber compounds better resistance towards swelling and increases the modulus at 200% elongation, tensile strength, hardness and abrasion resistance. The dispersion morphology of silicon carbide in the natural rubber composites was observed by scanning electron microscopy. The modified particles with improved interfacial adhesion between waste silicon carbide and natural rubber. Improvement in mechanical properties of the composites was obtained.

Closed cell rubber sponge applied as thermal insulator made from solid natural rubber (NR) was prepared by using Supercell DPT as a blowing agent. Rubber chemicals and STR 20, solid NR, were mixed on a two roll mill prior to prepare the specimen by hot press machine. Curing behaviors of the compounded solid NR with various types of sulfur and peroxide vulcanizations were characterized with moving die rheometer (MDR) at 150 and 170°C. Tensile and compressive strengths of the rubber insulator were measured by universal tensile testing machine followed by ASTM D412 and ASTM D395, respectively. Bubble size of the blown up rubber was inspected by an average maximum length of the bubble by using optical microscope. It should be notice from the experimental that all rubber formula both of sulfur and peroxide systems showed loading percentages to completely expand in a mold by about 38 to 48. Rubber insulator blown up with Supercell DPT used by semi-efficient vulcanization (semi-E.V.) unconcealed predominant results among all curing systems so that further investigations of the formulation as heat stuff will be discussed in next paper

A new ternary composite of W-SiCP/Cu(40vol%) was designed and prepared by low-temperature hot-press sintering. The micro-structural characterizations were evaluated by X-ray diffraction (XRD) and scanning electron microstructure (SEM), coefficient of thermal expansion is measured. When sintered at 950°C-100MPa-2h, the relative density of the W-SiCP/Cu composites as a function of W content all exceeded 97%. Due to the plastic deformation of Cu, higher densification W-SiCP/Cu(40vol%) composites can be achieved at a relatively low temperature. The composites are characterized by the relatively low coefficient of thermal expansion, bending strength and hardness. The values of thermal expansion indicate that thermal expansion can be precisely controlled by adding SiC particles.

This research work investigates the effect of using alkaline-treated continuous long pineapple leaf fibers (PALF) as reinforcement in bio-based poly lactic acid (PLA) polymer biocomposite. Alkaline treatment using NaOH solution was employed to improve the fiber-matrix adhesion, with the aim to enhance the mechanical properties of the biocomposites, in terms of its tensile and impact properties. In this study, both the plain PLA polymer and the PALF reinforced PLA biocomposites were prepared using compression moulding process. Thin films with nominal thickness of approximately 1 mm each were stacked in between continuous long PALF fibers prior to compression moulding via hot press machine to form biocomposites plate. Two types of mechanical testing were performed, i.e., tensile test (ASTM D3039) and impact test (ASTM D6110). Significant enhancements are observed when the plain PLA were reinforced with the PALF long fiber, with the biocomposites showing two times better the tensile strength and modulus, with the values of approximately 73.26 MPa in comparison to only about 34.85 MPa for the plain PLA and tensile modulus of approximately 2735.36 MPa in comparison to 1641.12 MPa for the plain PLA. The energy absorption of the biocomposites also showed promising results with a value of approximately 0.92 J/cm2 in comparison to only about 0.35 J/cm2 for the plain PLA. In addition, a scanning electron microscope (SEM) was used to scrutinize morphology of the PALF reinforced PLA biocomposites.

The application of natural fibers in composite is very encouraging because of its many benefits such as more environmental friendly and cost reduction. Recently, there is an interest on the application of kenaf-based material for high-end uses such as in automotive industry. In this research, mechanical properties of kenaf fiber reinforced polypropylene (KFRP) composite added with two different types of bio-based fillers, i.e., oil palm shell particle (OPSP) and rubber seed shell particle (RSSP) are studied. The composites were prepared by melt mixing of the materials using internal mixer, followed by compression molding process using hot press machine. The tensile and flexural strength were found to increase with the addition of OPSP as well as RSSP. However, KFRP composite added with RSSP showed better tensile, flexural and impact properties as compared to the composite added with OPSP. From microscopic observation of the raw OPSP and RSSP particles, it was observed that OPSP showed a more granular shape, while RSSP particles were flakier in shape. This difference in particle shape is believed to affect the mechanical properties of the composites as demonstrated in this study.

Polyimide (PI) composites have been widely used in a space science due to extraordinary properties, such as excellent mechanical and electrical properties, good thermal stability and chemical inertness, as well as high wear resistance. However, atomic oxygen (AO), as one of the main radiated constituents in low earth orbit, had an important influence on the structrural and tribological properties of the polyimide matrix. To investigate the mechanism of AO erosion on polyimide, MoS2/Al2O3/PI composites were fabricated by means of a hot-press molding technique and irradiated by AO in a ground-based simulation system. The chemical composition change of the irradiated surface was examined by X-ray photoelectron spectroscopy (XPS). Then, the friction and sliding wear behavior against GCr15 steel balls were evaluated in a ground-based simulation facility using ball-on-disk tribology test rig. The worn morphologies and radiated surfaces of the materials were observed by Scanning electron microscope (SEM) to reveal the wear mechanism. Experimental analysis indicated that oxidation induced by AO irradiation and degradation of PI molecular chains on the composite’ surface results in change in chemical composition and formation of “carpet-like” structures. Affected layer, gradually formed during the process of irradiation, plays an important role for wear performance of the materials increasing friction coefficient and wear rate. Incorporation of Al2O3 nanofibers and MoS2 nanoparticles is shown to be favourable for AO resistance, which is helpful for improvement in wear resistance of the PI.

Lead lanthanum zirconate titanate (PLZT) transparent ceramics have attracted more and more attentions for their unique electric-induced light scattering effects. The PLZT ceramics of 7.45 mole% lanthanum with different Zr/Ti ratios (Zr/Ti=68/32, 69/31, 70/30, 71/29, 72/28) were prepared by the hot-press sintering method. The X-ray diffraction patterns confirm that all the PLZT samples are perovskite structure without detected secondary phases. The SEM images of the fracture surfaces of the samples show that all the PLZT materials tend to fracture transgranularly, and exhibit fully dense and uniform microstructures. All the samples with different Zr/Ti ratios present typical relaxation ferroelectric phase transition characteristics with square shaped hysteresis loops. Noticeably, all the original PLZT samples show an excellent transparency in the wavelength range from visible to near-infrared, and they will become opaque after an appropriate electric field experienced. The opaque sample can also recover to the transparent state when an inverse compatible electric field acts on it. The contrast ratio of the sample increases firstly and then decreases when the Zr/Ti ratio increases from 68/32 to 72/28 (λ=632.8nm). The PLZT (7.45/70/30) material shows a maximum contrast ratio, which makes it promising to apply in optical modulators.

Utilization of natural fiber as reinforcing material is the latest trend in polymer science to produce higher strength with lower weight composite materials having wide range of applications. As a natural fiber, banana fiber is getting importance in recent years in the reinforcement arena of polymer composite. Two species of banana vizMusa sapientumandMusa paradisicaavailable in North East India were selected considering their higher fiber yield and adequate strength properties of the fibers. The chemical compositions, spectroscopic and thermal properties of these fibers were studied in order to study their suitability for commercial exploration. Low density polyethylene (LDPE)-banana fiber reinforced composites were prepared using hydraulic hot press. Physico-mechanical properties (e.g. tensile strength, flexural strength, elongation at break, Young's modulus) of the prepared composites were determined. The tensile strengths and flexural strengths of the composites increased while using LDPE 10 to 30 % of the fiber and then started to decrease gradually. Young moduli of the composites increased with the increase of fiber mass. Water absorption also increased accordingly with the increase of the fiber weight. The elongation at break decreased with increasing fiber quantity. The mechanical strength properties of chemically treated banana fiber-LDPE composites were slightly higher than the mechanically extracted fiber-LDPE composites. Structural analyses of the treated fibers were carried out by FTIR and XRD. These studied revealed due to the removal of noncellulosic constituents such as hemicelluloses and lignin the crystalline properties of the fibers were increased. All the properties of composite like tensile strength, flexural strength, water absorption capacity etc. plays a significant role in these polymer composite materials. Hence it can be concluded that banana fiber can be used as reinforced agent successfully in the composite industry as a sustainable building material.

Alumina ceramics are the most widely used structural ceramics, especially in aviation, spaceflight and war industry area. However, alumina is of covalent bond, with low fracture toughness and poor thermal shock resistance, which baffle the application of the alumina ceramics in engineering. In this paper, mullite fiber was used to improve its toughness and thermal shock resistance. Alumina-mullite composite ceramics were prepared by hot press sintering. The effect of mullite fiber on thermal shock resistance of ceramics was investigated through indention quenching method. Meanwhile, the mechanism of its reinforcing and toughening and the relationship between mechanical properties and addition of mullite fiber were also discussed.

Lead lanthanum zirconate titanate (PLZT) transparent ceramics have attracted more and more attentions for their unique electrically controlled light scattering effects. By the hot-press sintering method, a series of PLZT (X/70/30) ceramics with different La concentration (7.3, 7.4, 7.45, 7.5, 7.6 mole %) have been synthesized to figure out its influence on the electrically controlled light scattering performances. XRD patterns reveal the formation of a single-phase perovskite structure for all samples. The PLZT (7.3/70/30, 7.4/70/30, 7.45/70/30) samples exhibit a ferroelectric behavior, but with the La concentration increasing, the samples exhibit a tendency of a double hysteresis loop which is due to antiferroelectric phase coexisted. The temperature of maximum dielectric constant (Tm) of the PLZT (X/70/30) ceramics shifts from ~99 °C to ~87 °C with the increasing of La concentration at 1 kHz. All samples exhibit a high transmittance (61%, 0.35 mm) within the wavelength range from visible to near-infrared light. Depending on the La concentration, the light scattering behavior of PLZT ceramics exhibit two main types, in which PLZT (7.45/70/30) promises a unique potential application in laser modulators for its outstanding advantages of less energy consumption and relatively larger contrast ratio.

Fiber reinforced and aluminum phosphate-based composite was studied in this experiment. The composite was prepared through the process of lamination- hot press- sintering, binding material and fillers. The proper mixture ratio of Al2O3:AlPO4:H2O was 10:2.88:2.88.The slurry with this ratio was proper to prepare the composite. It indicated that the mechanical property of composite was excellent which was prepared by the slurry with this ratio. In order to improve the Mechanical property of silica glass fiber / aluminum phosphate composite, Al2O3 powders were graded in the slurry. Mechanical properties of composites were improved evidently.

In the present study, Ti (C,N)/Al2O3nanocomposite ceramic die material was fabricated through adding nanosize Ti (C,N) powders into micrometer Al2O3matrix by vacuum hot-pressing technology. Effects of the hot press sintering process on mechanical property and microstructure of the nanocomposite ceramic die material were investigated. The optimum hot-pressing technology with the sintering temperature of 1650°C, time duration of 15min and pressure of 30MPa was achieved. The microstructural morphology of the material was also analyzed. It reveals that the intergranular/intragranular microstructure and the resulted intergranular/transgranular fracture mode are the main causes for strengthening and toughening in the nanocomposite ceramic die material.

Al2O3-MgO, Al2O3-Y2O3 and Al2O3-MgO-Y2O3 composite ceramics were fabricated respectively by hot-press sintering technique. With the analysis of the mechanical properties and microstructure, it was found that single additive MgO could be more favorable to the grains’ refinement and densification than Y2O3; the composite additive including both MgO and Y2O3 was better than single additive MgO or Y2O3, because their interactions could improve the mechanical properties of the Al2O3 ceramics; The sintering temperature could be reduced by adding the suitable amount of composite additives.

Ti(C,N)-TiB2-WC composite ceramic cutting tool materials with nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo as sintering aids were sintered respectively at a temperature of 1550 °C for holding time of 1hour in vacuum by a hot-press technique. The effects of nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo on microstructure and mechanical properties of composites were compared and investigated. It is concluded that the wettability of nano-scale Ni and Mo to the composites is better than that of micro-scale Ni and Mo. The nano-scale whiskers were found in the composite ceramic tool materials with nano-scale additives. The addition of nano-scale Ni and Mo instead of micro-scale Ni and Mo could make the flexural strength and fracture toughness of Ti(C, N)-TiB2 –WC composites have a promotion, but could not make the hardness of the composites increase in this study.

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.

The development of polyimide (PI) composites, particularly for use in aerospace and tribological applications, has gained importance over the past decades. However, there have been scarce studies on the ultraviolet (UV) or atomic oxygen (AO) irradiation characteristics of the polyimide composites, the understanding of which may aid in expanding its application in space environment. To study the irradiated effects of UV and AO on the tribological behaviour of the PI composites, glass fibers (GF)-reinforced PI composites filled with Talc were irradiated by UV or AO in a ground based simulation system. Glass fibers (GF) reinforced PI composites filled with talc were fabricated by means of a hot press molding technique. The volume contents of the talc (10, 20, 30 %) were chosen to study the effects of filler content on the tribological behavior of the composites, while the proportion of the glass fiber was kept at 15 vol %. To contrast the different effects of UV and AO irradiation on the tribological properties of the composites, experiments without irradiation and after UV or AO irradiation were conducted. The specimens of the composites were irradiated with UV for a period of 4h, while AO irradiation chosen for 6h. Dynamic mechanical analysis (DMA) and thermal gravimetric analysis (TGA) measurements were conducted. The friction and wear behaviors of the composites, rotating against GCr15 steel balls, were investigated on a ball-on-disk test rig. at room temperature and at a rotating speed of 0.1256 m/s and a load of 1N. Experimental results revealed that the composites exhibited high modulus and wear rate values with increasing talc content, but low coefficients of friction (COF). After AO irradiation, the COF of the composites increased, but UV irradiation had no obvious effect on the tribological property of the composites. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) study of the composite surface showed that the chemical composition of the surface changed after UV irradiation because of the photooxidation and rough surface or even mountain-like structures were formed after AO erosion. The experiments indicated that the different space environments had an important effect on the tribological properties of the polymer composites. It is expected that this study may help expand the application of the polyimide composites in the field of space.

0-3 nanocomposites of PVDF with varying volume percents of strontium doped PZT have been synthesized using a combination of a modified solution casting process and the hot press technique. The nanocrystalline PZT used prepared from the sol gel route and was in the calcined state. An increase in the volume percent of PZT caused an increase in the dielectric constant, dielectric loss and piezoelectric charge coefficients. The experimental dielectric constants gave a perfect fit to the theoretical Furukawa model. However, no significant trend is perceived for the dielectric loss. SEM and XRD aided in determining the morphology and the crystalline phases in PVDF, PZT and PVDF/PZT composite. TG/DSC was done to confirm the percentage crystallinity of PVDF. A comparison with samples prepared from the conventional solution casting process has also been given. Composites prepared from the modified solution casting process using nanocrystalline strontium doped PZT give better piezoelectric properties as compared to earlier works.

Al2O3 reinforced Ti3A1C2 in situ composites have been fabricated by reactive hot pressing method from the mixture of Ti, Al, TiO2 and C. The phase formation and transformation regularity of samples during the process of hot pressing were investigated in detail by X-ray diffraction (XRD). The microstructures of the synthesized samples were observed by scanning electron microscopy (SEM). The results show that the reactions of powder mixture during the hot press sintering could be divided into three stages: firstly, Ti reacted with Al to form TiAl intermetallics, and Ti reacted with C to form TiC, respectively; and then TiO2 was reduced by Al to form Al2O3, TiAl intermetallics reacted with TiC to form Ti2A1C; finally Ti3A1C2 was formed through the reaction between Ti2A1C and TiC.