16^th International Conference on Emerging Materials and Nanotechnology Mar 22-23, 2018 London, UK

Mr, Bin Li is a Senior Scientist in Shanghai Institute of Technical Physics, Chinese Academy of Sciences. His research focuses into infrared coating materials and infrared-transmitting materials, including rare-earth fluorides, oxides and narrow gap semiconductors

Although some rare-earth fluorides were currently used in infrared antireflection as low-index evaporation materials in order to substitute for radioactive thorium fluoride (ThF4), the higher tensile stress presented in the layers will deteriorate the reliability and durability of the interference multilayers. Stress in the layers significantly influence not only the mechanical performance of interference multilayers such as thermal cycling life and fatigue properties but also their optical behaviors due to cracking or interfacial delamination. Most importantly, any bending or deformation of the substrate caused by stress will also affect the performance of the antireflection coatings. Therefore, the relief of the stress in the layers is a critical process. The stress in the film after the deposition process is the sum of three different types of contributions. First, there is the intrinsic stress evolving in the layer during deposition. Secondly, the thermal stress appears during the cooling process, caused by a mismatch between the coefficients of thermal expansion of the substrates and the materials deposited. Finally, the adsorptive stress occurs once the finished coating is open to air with the adsorption of moisture and impurities. The magnitude of stress can vary depending on the conditions of deposition. Since the substrate materials, deposition process, moreover, the difference between the deposition temperature and the ambient temperature, were completely controlled to be identical, only the contribution resulting from intrinsic stress is basically related to the chemical composition of the films. In our investigation, a new infrared low-index evaporation material, the admixture of praseodymium fluoride (PrF3) with barium fluoride (BaF2) was exploited. The stresses in thin films deposited on Si strips using electron beam evaporation from the sintered pellets of PrF3 admixed with a different amount of BaF2 were measured. It is disclosed that the stresses in the layers of PrF3 can be greatly reduced with the increasing amount of BaF2 in thin films.

Prof. Jing Lu has her expertise in surface modification of nano carbon materials and the corresponding application fields. After got her PHD degree in Material Science, she worked in Mechanical Engineering and focused the research on ultra-precision machining of wide bandgap semiconductor. She has developed a novel method to coat diamond core with oxide shell and significantly improve the interface bonding between the abrasive and the polymer marix. The related achievement have been published in Nano letters, Nanotechnology, Carbon, and et al.

The semi-fixed abrasive polishing film which was based on sol-gel (SG) technology exhibited favorable machining performance in processing semiconductor power device materials. Compared to the fixed diamond abrasive tool, SG semi-fixed diamond abrasive tool could easily obtain a smooth and scratch-free surface with nanometer scale roughness due to the effect of abrasive yielding. However, the strength of SG polishing film is relatively low which restrains its further development. Graphene is a two dimensional material of carbon atoms in a hexagonal arrangement with remarkable mechanical and electrical properties, high thermal conductivity, specific surface area and good compatibility. Therefore, it is widely used in a range of applications, such as electronics, solar cells and electrochemical sensors, especially as a multifunctional nanofiller. Compared with graphene, Graphene oxide (GO) has excellent mechanical properties, favorable compatibility and solubility. In this paper, graphene oxide (GO) was used to enhance the strength of the polishing film which was fabricated from sodium alginate. The dispersing stability of the GO, microstructure and tensile strength of the polishing film have been investigated by Zetasizer, three-dimension optical microscope, FTIR spectroscopy, scanning electron microscope and electronic universal testing machine. The results revealed that diamond abrasives, sodium alginate and graphene oxide could mix with each other homogeneously and the mechanical properties of the as-prepared films were improved significantly over that of the pure SG polishing film. The tensile strength of the SG film with GO increased by 52.67%, 63.13%, 28.28% compared to sheer SG film when the concentration of GO was 0.01 wt%, 0.05 wt%, 0.10 wt%, respectively. Furthermore, the addition of graphene oxide facilitated the interfacial interaction between GO sheets and polymer matrix.

Changcai Cui has completed her PhD from Harbin Institute of Technology (HIT). She is the Head of the department of precison measurement technology and instrumentation of Huaqiao University. She has published more than 70 papers in journals and confererences and has been a corresponding reviewer of some journals.

Ultrasonic additive manufacturing is a new rapid prototyping process for creating metal composite materials. Since ultrasonic additive manufacturing is capable of bounding many different metal materials at near room temperature within several micro seconds, it is possible to produce composite materials with superior performances very fast with protecting gas system. Because of absence of phase change during bounding of two metal foils, the shape processed won’t deform much like procedure with phase change. In this work, a review of researches on metal composite materials produced by ultrasonic additive manufacturing is presented. Firstly, the principle of ultrasonic addictive manufacturing is introduced along with controlling factors provided by this equipment. Then the application fields for metal composite materials are summarized and the performances required for these new materials are discussed. Thirdly, an investigation of material testing systems for metal composite materials is conducted and limitations of these methods are analyzed. Finally, further application possibilities of metal composite materials are discussed and some problems for further research are also presented.

Xipeng Xu is President of Huaqiao University. He has his expertise in machining technology and functional usage of diamond materials. He is executive member of International Committee for Abrasive Technology (ICAT) and gets over 140 technical papers publication in related journals and conference.

Titanium dioxide (TiO2) is well known as a semiconductive oxide that has attracted substantial attention because of its applications in photocatalysts. Decorating TiO2 nanoparticles on nanocarbon substrate can prevent the nanoparticles from aggregation, increasing the active specific area and raising the utilization rate of TiO2. Unlike the commonly used sp2-bonded carbon materials, Nanodiamond (ND) with sp3 bond has more outstanding thermal stability and oxidation resistance. As most of the synthetic methods for achieving crystalline TiO2 require high temperature heat treatment under aerobic atmosphere, it may cause damage to the nanocarbon support material. Our previous research showed that compared with other methods, the isothermal hydrolyzing procedure can directly obtain crystalline metal oxide from aqueous solution without annealing. In this study, we used this simple and soft one-step method to prepare ND-supported crystalline TiO2 nanoparticles (TiO2/ND). The morphology, structure, and composition of the composites were characterized with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The electrochemical catalytic performance of TiO2/ND for nitrite was investigated with electrochemical experiments. The nanocomposites displayed a unique feature of having NDs inside and crystalline TiO2 nanoparticle coatings on the surface of the ND powders. The phase, structure, and thickness of the TiO2 coating could be adjusted by the reaction time. The electrochemical results indicated that the TiO2/ND prepared by hydrolyzing for 16 h exhibited higher electrocatalytic activity than the others. And the catalytic ability of the nanocomposites was higher than those of the initial ND and P-25 TiO2 towards the oxidation of nitrite.

Jiangbo Sha, received the Ph. D. degree from Xi’an Jiaotong University, Xi’an, China, in 1994. He was a Research Fellow with KNIST and NIMS, Japan, and Nanyang Technological University, Singapore, from 1998 to 2004. He joined the School of Materials Sciences and Engineering Institute, Beihang University, China, as an Associate Professor in 2005, where he has been a Full Professor since 2009. He is interested in novel high-temperature structural materials, such as Nb-Si, and Co-Al-W based alloys, and fatigue behaviours of metallic foils. He found some compositions of these alloys with excellent strength at temperatures from 800 to 1500C.

Tensile behaviours and Slip band-grain boundary interactions of γ’-Co3(Al,W)-strengthened Co-9Al-4.5W-4.5Mo-2Ta-0.02B-(0.01, 0.05, 0.1 and 0.2)Ce alloys (referred to as 0.01Ce, 0.05Ce, 0.1Ce and alloy and 0.2Ce alloys, hereafter) were investigated in-situ using SEM and TEM. Under tension at room temperature, the 0.01Ce and 0.05Ce alloys showing higher strength and elongation fail in a transgranular dimple mode, while the 0.1Ce and 0.2Ce alloys with lower strength and elongation fracture in a mixed transgranular-intergranular mode owing to the Co3W debond with the grainboundary. The four alloys exhibits tensile flow stress anomalies at temperatures about 700°C. For the 0.01Ce alloy with a γγ’-Co3(Al, W) coherent microstructure, the {1 1 1}<1 1 0> dislocations initiate in the channels and subsequently cut into the neighboring ’ phase. A low-angle grain boundary (LAGB) is necessary for the slip band transfer mechanism. The slip bands transfer through the LAGB when the alignment factor M > 0.8 with the incoming easy-slip system and the Schmid factor > 0.3 on the outgoing slip system. The high-angle grain boundaries (HAGBs) usually have a low M value and the incoming slip bands are blocked at the HAGBs without transfer; instead, independent slip systems with the highest Schmid factor in the neighbouring grain are activated. The plastic deformation of the γγ’-Co3(Al,W) microstructure and the slip band-grain boundary interactions lead to elongation larger than 16.4% of the 0.01Ce and 0.05Ce alloys. With some Co3W precipitates at the grain boundary of the 0.1Ce and 0.2Ce alloys, the slip bands bypass, cut through, or sometimes are arrested by the precipitates, resulting in a low elongation less than 2.1% and a mixed dimple and cleavage failure.

Agata Sotniczuk is currently a PhD student at Faculty of Materials Science and Engineering, Warsaw University of Technology. In her work she focused on corrosion behavior of nanocrystalline metals, especially titanium and aluminium alloys. One of her main interest is the influence of microstructural defects, like dislocations and grain boundaries on the passive layer formation is solutions simulating body fluids. This subject was also a topic of her Master Thesis which was awarded the first price from the Polish Corrosion Society. Her main investigation tools are electrochemical tests (impedance and potentiodynamic) together with electron microscopes (SEM, TEM) for microstructure characterization.

Due to the ageing of human population, the number of people suffer senses diseases increasing inevitably. For this reason there is a constant necessity for new opportunities which allowed to examine as huge group of people as possible. The mobile medical devices, which can be quickly relocated to the distant places, will undoubtedly improve accessibility of the screening senses tests even in the underdeveloped areas. However, the mobility of designing cabin put a special requirements on its construction. The high mechanical strength related to density, which allow to the mass reduction, is essential for constructive materials used in designing cabin. Moreover, frequent transport provide possibility of exposure constructive elements on different environmental conditions so their high corrosion resistance is also important. The solution strengthened 5xxx aluminium alloys fulfil this requirements. Therefore, plates made from 5xxx alloy were selected for creating the mobile medical construction. Due to the specific shape of cabin, aluminium plates had to be bent in different angles. Moreover, the opportunity of cabin installation and reinstallation required introducing mounting holes for screw joints in constructive elements. Both of these processes can make an impact on the microstructure and consequently on the properties of the aluminium elements. In this study the influence of plastic deformation and the presence of mounting holes (cut by laser) on the microstructure, mechanical and corrosion properties of aluminium plates was investigated. For these purpose following investigations were performed: microstructure analysis (OIM, SEM+EDS, TEM), evaluation of the mechanical properties (microhardness measurements and static tensile tests also using miniature tensile specimens), analysis of the corrosion resistance (neutral salt spray tests in corrosion test chamber). Obtained results allowed to check if the existence of bends and mounting holes has a deleterious effect on the construction. There are no doubts that this study gave an insight if any modification of construction or additional material treatment have to be taken into consideration. This research was financially supported by The National Centre for Research and Development in Poland under Grant STRATEGMED1/248664/7/NCBR/2014.

Donata Kuczynska is a PhD student and has her expertise in evaluation of surface properties of the materials, especially in biomaterials. Her main interest is interaction of titanium surface with the plasma proteins (albumin and fibronectin) and cells. She deals with comprehensive surface characterization of physicochemical properties such as: chemical composition, roughness, topography, wettability and surface free energy. She has experience in surface analysis techniques - AFM Atomic Force Microscopy, Optical Profilmetry, XPS Spectroscopy, Auger AES Spectroscopy and Fourier FTIR Spectroscopy. Currently she is working on laser surface texturing of titanium and its alloys.

In this study we present the results of microstructure and acoustic properties of the composites for lightweight medical cabins. Small, lightweight and self-operated cabin can be a great tool to perform screening tests of the variable senses. This kind of cabin must meet a number of requirements, and one of them is good soundproofing. There are several problems to combine good acoustic properties and lightweight construction. A suitable acoustic properties can be obtained using special composite panels with the high surface topography, proper composite thickness and the proper type of filling. Therefore, in this study the microstructure and acoustic properties of several lightweight polyester resin – fiber glass composites were characterized. Analyzed panels differed in terms of thickness (3 and 10 mm), surface topography (geometrical diffuser or not) and type of filling (wool filling and high density polyurethane foam conglomerate). For characterization purpose, the following methods were used: scanning electron microscopy observations, electron dispersive spectroscopy measurements and the density measurements. Special emphasis was placed on the measurements of the particle size, voids and their share in the matrix. Acoustic measurements where performed using unique acoustic equipment setup. Microscopic observations allowed to define small (approx. 3%) porosity, variable Gelcoat thickness and depict admixture size (average 2.74 μm) and their content in the matrix (about 16%). EDS analysis confirmed that particles present in the matrix are dolomite powder, which is commonly used as an additive to increase the strength of the composite and its contraction. Acoustic analysis showed that increased laminate thickness improves sound damping factors, that presence of the sound diffuser slightly reduces the length of the sound's decay and more dense filling improves both of this parameters. The results show high potential of analyzed composites as lightweight construction materials with simultaneous good sound absorption properties.

Cheng-Ying Lee majors in materials science engineering at National Tsing Hua University and specializes in thermal management. At the early stage of her research work was raising the thermal conductivity of Diamond/Cu Composites as heat spreader. In recent days, she focuses developing using low melting point alloy as thermal interface material to increase thermal transfer efficiency. She expects her research result will be more competitive than current commercial products.

Diamond/Cu composites for the use of heat spreader were fabricated via pressureless liquid phase sintering process. Minor-addition of Zr was added into the matrix to improve the wettability between diamonds and Cu matrix. A high thermal conductivity of 716 W/mK was obtained for the 50 vol% diamond/Cu composite. Composites fabricated by Cu/Zr flake method can reduce the surface roughness from 35 μm to 1.6 μm, which is suitable for joining with commercial substrates. AlN, Si, and Al2O3 substrates were joined with composites by commercial lead-free solder paste and liquid metal. Liquid metal joined packages had great performance opposite to the solder pasted ones with the highest thermal conductivity of 342 W/mK in the couple of the Si substrate. For AlN, Si and Al2O3 substrate joined packages, average thermal conductivity were 299, 322 and 148 W/mK, respectively. On the reliability of thermal cycle tests for joining packages, the lower thermal cycle (25-85 C) was to simulate the operating environment and the higher thermal cycle (25-200C) for fabricating environment. It showed great reliability with above 78% residue thermal conductivity after lower temperature 1000 thermal cycles and 79% after higher temperature 5 thermal cycles.

Chenghao Deng is a P.h.D. student focused on the research of physical properties and applications of carbon nanomaterials. He has succeeded in characterizing the mechanical, thermal, electrical and structural properties of single carbon nanocoils. He developed some simple and economic methods to fabricate stretchable or flexible sensors based on carbon nanomaterials, towards wearable or micro/nano scale applications.

In recent decade, wearable electronic device and sensor attracted intense attention with the development of smart systems, owing to their effective interactions with human and machine motions. Despite the tremendous progress, it is still a challenge to develop a highly sensitive, stretchable and low cost sensor. Herein, a super stretchable and sensitive strain sensor fabricated by a simple peeling off approach is reported. The strain sensor is prepared by peeling off a thin as-grown carbon nanocoil (CNC) film from substrate using a stretchable polydimenthylsiloxane (PDMS) film or a flexible adhesive tape. Here we take advantages of the spring-like morphology, and the original network of CNCs. The spring-like morphology of CNCs determines the point contact among single CNCs and the super stretchability of CNCs. The original networks of CNCs on substrates make it much simpler and cheaper for sensor preparation. The sensor is used to detect pressure, tension and bend. The strain range and maximum real-time gauge factor reach 260 % and 190 respectively, with a rapid response (less than 12 ms). The contrary resistance responses under tension and bend make it possible to distinguish the direction and type of strain. The sensor is used to monitor a strain in wide range, from human pulse to the impact of a 0.9 kg weight. The high sensitivity and stretchability, easy and cheap fabrication, effective interaction with human motions suggest the great potential applications of the sensor in wearable strain sensor and smart system.