Abstract: Recently, people devote to the development of Ni-free shape memory alloys in order to
avoid the Ni-hypersensitivity and toxicity and pursue absolute safety. The shape memory effect and
superelasticity have been reported in the biomedical Ti-Nb based alloys. The purpose of this paper
is to report the phase constitution, tensile property, shape memory effect and corrosion resistance of
the Ti-Nb alloys. The phase constitutions of the Ti-Nb alloys are investigated by means of X-ray
diffraction (XRD). The results reveal that β+α′′ phases are presented in the Ti-35Nb alloy and only
β phase in the Ti-52Nb alloy at room temperature. The tensile test and bending tests indicate that
the Ti-35Nb alloy exhibits shape memory effect. The shape recovery ratio is near to 80% when the
bending strain is 4.4% and decreases with the increase of the total bending strain. The corrosion
resistance of the Ti-Nb alloys in the Hank's solution and artificial saliva (pH=7.4) at 37 are
investigated by OCP, Tafel and anodic polarization methods. The results indicate that the Ti-35Nb
alloy has a better corrosion resistance in the artificial saliva and can replace the Ti-Ni alloy in the
dental application. In the non-oral condition, the Ti-52Nb alloy may be preferable.
Abstract: Magnetic nanoparticles have attracted intensive attention for their wide applications as
biomaterials and magnetic storage materials. Polyurethane is one of the most biocompatible
polymers and has been used widely in vivo. In this paper, the magnetite nanoparticles were
synthesized by chemical precipitation under different conditions. The as-prepared samples were
characterized by X-ray diffraction and transmission electron microscopy, and their magnetic
properties were evaluated on a vibrating sample magnetometer. Then the magnetite nanoparticles
with different amounts were doped into polyurethane directly and composite films were made.
Reinforced by the inorganic particles, PU composite films were also characterized by Fourier
transform infrared spectra and mechanical tests., and the surface morphology of the composite film
was observed by Atomic Force Microscope The results showed the composite material was
reinforced by magnetic nanoparticles and also showed magnetic behavior. This kind of composite
materials have the potential to be used as hyperthermia treatment in biomedical field, like coatings
on cardiovascular stents.
Abstract: In this work, potential problems with the application of polymer matrix composites
(PMC) in extreme environments  is discussed. Then, two specific examples of the applications of
PMCs in high voltage [2-7] and high temperature [8-15] situations are evaluated. The first example
deals with damage evolution in high voltage composite insulators [2-7] with PMC rods subjected to
a combined action of extreme mechanical, electrical and environmental stresses. These insulators
are widely used in transmission line and substation applications around the world. Subsequently,
advanced high temperature graphite/polyimide composites [8-15] are evaluated for aerospace
applications. The composite investigated in this project were used to manufacture and successfully
test a Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket
engine, which is one possible engine for a future single-stage-to-orbit vehicle .
Abstract: This paper quantifies the effects of geometry, the loading mode and the specimen size on
fracture toughness of the API X65 steel, via plane strain finite element (FE) damage analyses using
the GTN model. The validity of FE damage analyses is checked first by comparing with experimental
test data for small-sized, cracked bar test. Then the analyses are extended to investigate the effects of
the relative crack depth and the specimen size on fracture toughness. It is shown that fracture
toughness of the API X65 steel increases with decreasing the relative crack depth and increasing the
Abstract: TiCp/ZA-12 composites have been fabricated by XDTM method and stirring-casting
techniques. The tests for mechanical properties reveal that the tensile strength and strength
increase with increasing fraction of TiC particles. When the fraction of TiC particles increase up to
10%, the tensile strength and yield strength are 390MPa and 340MPa, respectively and they increase
by 11% and 17% than that of matrix respectively. From the analysis of fractography we can see that
mixed fracture of cleavage fracture and dimple fracture exists in the TiCp/ZA-12 composites, and
fractured particles are not found. Finally the fracture model of composites has been established based
on the experimental results.
Abstract: A new thermal spraying technique, electro-thermal explosion directional spraying
(EEDS), was used to prepare NiAl intermetallic coatings. The microstructure, elements distribution
and phase structures were determined by means of SEM, EDAX and X-Ray diffraction,
respectively. Micro-mechanics properties were tested by using nano-indentation tester. The wear
resistance of the coating was also investigated. Results showed that NiAl coating was characterized
by compact construction. The main phase of the coating was Ni-Al and the content of oxide was
little. The obvious elements diffusion showed that the bond between the coating and the substrate
was metallurgical one. The nano-hardness and the modulus were 7.6 GPa and 218.8 GPa,
respectively. The coatings processed good wear resistance and the main wear failure mechanism
was the micro-plowing.
Abstract: Scattering of SH wave by a crack is studied in elastic half space with a removable rigid
cylindrical inclusion by Green’s function, complex function and moving coordinate method. In half
space, firstly the scattering wave function of removable rigid cylindrical inclusion is constructed;
next a suitable Green’s function is solved for present problem, then using crack-division to make a
crack. Thus the solution of problem can be obtained. Numerical examples are provided and
Abstract: The microscopic processes of internal force redistribution of structural system due to
dead load failure or fatigue failure of structural element and failure mechanism of cumulative
damage under outside loads is discussed in this paper. Considering the influence of cumulative
damage to the residual strength and the reasonable time of dead load failure selected, the next step
calculation of cumulative damage has a clear quantitative time. Reasonable expression is provided
for the establishment of the equation of safety margin. By an example, the reliability index, which is
gained by rough conservative considering the time of dead load failure selected, is compared with
the reliability index, which is gained by using the method of this paper. The method of this paper
coincides with the engineering fact by analysis. A reasonable method is provided for reliability
analysis which structural system is considered dead load and fatigue failure at the same time.
Abstract: In the piezoelectric truss structure with many random parameters under incipient defect,
taking into consideration the mechanical-electric coupling effect under electric load and mechanical
load, the formula of safety margins of bar have been proposed by the fracture intensity, bar section
area and loads as random variables. On the base of above research, stochastic finite element method
is adopted to attempt to analyze reliability of the piezoelectric truss structure. In the end, the
example is given to demonstrate the influence of voltage and of damage on reliability index of the
piezoelectric truss system.
Abstract: In present paper, the mechanical properties and fracturegraphs of Mn-rich polycrystalline
alloys are investigated by compression tests and scanning electron microscope (SEM) observations.
It is shown that the fracture strength and the rupture strain decrease with the increase of Mn content.
It is suggested that the substitution of Mn for Ga reduces the ductility of Ni-Mn-Ga alloys. SEM
observations of fracture surface show us typical intergranular crack. There are many little holes and
micro-cracks on the grain boundary, which weakens the bond strength of grain boundary causing
the intercrystalline cracking.