Applied Mechanics and Materials Vols. 184-185

Abstract: Polylactic acid (PLA) is often applicable in biomedical because in environment it degrades into carbon dioxide and water. This study aims to prepare sandwich-structure PLA/ Tencel composite nonwoven, following by its property test for evaluating effect on wound dressing. In this study, PLA fibers, blended with Tencel fibers, were made into nonwoven fabrics based on nonwoven processing technology. After that, their tensile strength, tearing strength and softness were tested for evaluating nonwoven fabric properties. The result displays that, PLA nonwoven fabrics show higher tensile strength and tearing strength than Tencel nonwoven fabrics.

Abstract: The coconut carbon/cotton interwoven fabric has good absorbing ability on formaldehyde. In this paper we adopt the satin weave and weave The coconut carbon/cotton interwoven fabric, then carry on the nano-sized TiO2 finishing, can reach the optimum process of the nano-sized TiO2 finishing, then study and test the property of adsorption and degradation formaldehyde after finising.

Abstract: The atomic-scale microstructure and electron emission properties of boron and sulfur (denoted as B-S) codoped diamond films grown on high-temperature and high-pressure (HTHP) diamond and Si substrates were investigated using atom force microscopy (AFM), scanning tunneling microscopy (STM) and current imaging tunneling spectroscopy (CITS) measurement techniques. The films grown on Si consisted of large grains with secondary nucleation, whereas those on HTHP diamond are composed of well-developed polycrystalline facets with an average size of 10–50 nm. Large tunneling currents were observed at some grain boundaries, and the emission character is better at the grain boundaries than at the center of the crystal. The codoped films grown on HTHP diamond have an almost uniform electron emission efficiency at grain boundaries or crystalline facets, which indicates that the doped atoms are uniformly distributed in the films. The local I-V characteristics for films deposited on Si or HTHP diamond substrates indicate n-type conduction.

Abstract: The wave-like Ni is synthesized without any impurity via varying the addition of surfactant PVP, its microwave absorption can be attributed to dielectric loss and magnetic loss, and exhibits an maximum absorption value of -14.19 dB at 14.2 GHz.

Abstract: Nano-structured Al2O3-13%TiO2 coating was deposited by air plasma spraying. Wear properties of the coatings under different load trough SRV friction and wear testing machine were studied, the results showed that wear mass loss of Al2O3-13%TiO2 coating by plasma spraying slide with ZrO2 and Si3N4 increase with load increasing, but the difference is that wear loss of coaing slide with Si3N4 ¬is lower than the coating slide with ZrO2 when load is less than 40N. Opposite phenomenon will occur when load is higher than 40N.The wear surface morphology was analyzed trough scanning electron microscopic, the results showed that coating slided with Si3N4 ball when matching at low loads, with a shallow furrow shape grinding. There were wide and deep furrows while at higher loads. Coating slide with ZrO2 ball has no obvious cracks, no layer spalling.Wear was occurred by micro cutting.

Abstract: The article briefly introduced the wearing characteristic and the test method of fiber knitted fabrics, like comfortableness, fastness, and the banana property. Finally use the fuzzy comprehensive evaluation method to analyze and estimate the wearing characteristic of banana fiber knitted fabric. And then reach a kind of stitch with the optimum wearing characteristic.

Abstract: The effect of Ce on modifying inclusions of 2Cr13 stainless steel was studied by metallographic examination, SEM and electron spectroscopy. Thermodynamic calculation was used to analyze the formation of RE inclusions in 2Cr13 stainless steel. The result shows that MnS can be entirely replaced by Ce2O2S and CeS that are spherical.

Abstract: In the present paper, thermo-mechanical simulation of ultra-high strength ferrite-bainite dual phase (DP) steel was performed using a thermomechanical simulator. Continuous cooling transformation (CCT) diagram was constructed for DP steel. The effects of composition and cooling rate on the kinetics and products of phase transformation and the form of the CCT diagram were investigated. The results have shown that the α→γ transformation in DP steel was found to be more sluggish due to the addition of alloying elements. The segregation of manganese and niobium at austenite grain boundaries is expected to cause a solute drag effect, thereby reducing the rate of γ→α transformation in DP steel. The pearlite transformation region disappeared for cooling rates from 0.1 to 20°C/s. The microstructure comprises of bainite and martenite was obtained at fast cooling rate. The present steel is expected to have a higher hardenability.

Abstract: Ceramics and metallic material are commonly used in biomedical filed. Ceramic material, such as hydroxyapatite (HAP), is bioresorbable and has osteoconduction and osteoinduction. Metallic material, such as stainless steel (SS), possesses good mechanical properties and chemical stability. Thus, the study aim was combination of the two together can form the bone scaffold applied in bone tissue engineering, providing desirable support, cell growth, and cell attachment for bone tissue. This study method is braid the SS filaments into a three-dimensional structure of braid. By electrochemical technique, HAP is then coated on the braid, forming the three-dimensional HAP/SS bone scaffold. Simulated body fluid, the electrolyte solution, is heated into various temperatures to simulate the environment, and the current supplied in the electrochemical technique remains constant. A scanning electron microscope (SEM) observes the surface of the scaffold, and energy dispersive spectrometer (EDS) further evaluates the HAP attachment in terms of calcium-phosphorus (Ca/P) ratio, determining the optimal Ca/P ratio that is similar to that of human bone tissues to accelerate recovery of bone tissues. The result shows three-dimensional HAP/SS bone scaffolds are covered with HAP particles.

Abstract: The epoxy resins were toughened with reactive core-shell nanoparticles(CSNPs) with butyl acrylate (BA) as the core and methyl methacrylate (MMA) copolymerizing with glycidyl methacrylate (GMA) as the shell. The chemical structure of the CSNPs was characterized by FT-IR. The morphology of toughened epoxy networks were analyzed by SEM and TEM, and their adhesion properties were also detected. The results show that mixing methods and CSNP concentration have great influence on the morphology and adhesion properties of the toughened epoxy networks. CSNPs are uniformly dispersed in the epoxy resins by the grinding method. The modified epoxy networks obtained from the modified epoxy networks prepared by the grinding method(MEPN2) with 10 wt% CSNPs show the best adhesion properties, and the increase in maximum peel strength, 25°C sheer strength and 150°C sheer strength of the modified epoxy networks is 401.3% , 46.9% and 27.6% respectively over the unmodified epoxy networks due to the small-scale coagulations of CSNPs.