Applied Mechanics and Materials Vols. 687-691

Abstract: In this research, the Effect of extrusion pass on microstructure and transformation temperature of NiTiNb alloy was researched. The results shows that ECAP can efficiently break the hard and brittle (Ti, Nb)₂Ni phase. At the same time, β-Nb phase particles were precipitated and grow up after ECAP process.Due to enhancement of interfacial energy, train energy and non-chemical free energy, transformation temperatures including: As, Af, Ms and Mf increases with extrusion pass.

Abstract: In this paper, characteristics of SMA were analyzed and the research basis was researched. The connecting mechanism and mechanism of pipe coupling was introduced. Otherwise, in our research, after connecting by pipe coupling, the pipe can endure high pressure and occur blasting when the pressure reaches to 84MPa.

Abstract: Silicon is the essential element to phytoplankton, determining the growth of phytoplankton. Phytoplankton is the basis of the marine food chain, as well as phytoplankton has tremendous capacity to absorb carbon. Phytoplankton and human determine the change of atmospheric carbon collectively, so the earth system is able to maintain the dynamic balance of the emission of anthropic carbon and the absorption of carbon by phytoplankton. This paper analyzed the effects of Silicon to the growth of phytoplankton, the absorption of CO₂ by phytoplankton, the biogeochemical process of silicon, and revealed the effects of silicon to the change of phytoplankton growth and atmospheric carbon.

Abstract: A new theoretical model is proposed to describe the mechanical properties of bimodal nanocrystalline (BNC) materials.In this paper, we have studied the effect of grain size on the constitutive behavior and fracture of BNC materials. During the plastic deformation, dislocations emission from crack tips on the constitutive behavior of BNC materials are also analyzed, it is found that the nanocracks make a positive effect on the strain hardening instead of leading catastrophic failure. Numerical calculations have been carried out according to the model, the results show that the model can describe the enhanced strength and ductility of BNC materials successfully.

Abstract: The latest R&D of new-type titanium alloys and their aviation applications as well as the newly developed processing technologies in China have been reviewed in this paper. To meet the requirements of high performance and low cost design of aviation-oriented titanium alloys, great efforts and achievements have been made in establishing a system with Chinese characteristics, in which the low-strength-and-high-toughness titanium alloy (such as Ti45Nb alloy used for fasteners and TA18 for tubes & pipes), the medium-strength and high-damage-tolerance titanium alloy (such as TC4-DT used for large-integral airframe structures), the high-strength and high-toughness damage tolerance titanium alloy (such as TC21 used for large-integral airframe structures), and the ultra-high strength titanium alloy (such as TB8) are included. Some new processing technologies such as quasi-β forging and quasi-β heat treatment, integral isothermal forging and electron beam welding, have been demonstrated to be able to markedly enhance the properties of titanium alloys, which is regarded to be very important in increasing the application amount and level of titanium in aviation industry.

Abstract: We present a method to fabricate superhydrophobic surfaces on copper substrate using reciprocating type high speed wire cut electrical discharge machining (HS-WEDM) and self-assembly technology. Herein, single factor experiment was used to investigate the influence of several major parameters of the wire electrical discharge machining processing, such as pulse width, pulse gap (pulse interval) and power tube, on the contact angle of resulting surface. Results show that a composite structure, composed of craters and projections, is fabricated on the copper surface, which is the key reason of superhydrophobicity. With the change of pulse width, pulse interval, and the number of the power tube, the hydrophobic properties of resulting copper surface was changed. This paper provided the theoretical support for industrialized fabrications of super-hydrophobic brass surface.

Abstract: Because of difficulty in deep ion implantation, the recessed gate structure has been favored in SiC SIT. In order to improve the frequency, it is a good method to decrease the gate length by eliminating the side wall ion implantation affection. We developed normally-on RF 4H-SiC SIT with high small signal gain. The effect of forming the side wall protection between the source mesa and the gate area was simulated

Abstract: Based on the solid - liquid two-coupling theory, Use abrasive medium viscosity-temperature characteristics related to the mathematical model, using solid - liquid two-phase solution method Mixture models and standards, turbulence model combining with common rail pipe hole as the research object, choose different initial temperatures and processing procedures, numerical analysis was carried out on the flow channel wall temperature and turbulent kinetic energy. Using numerical analysis software FLUENT Abrasive Flow Machining rail tube orifice structure was three-dimensional numerical analysis; obtain a steady-state pressure, dynamic pressure, velocity, turbulent kinetic energy image, to study Abrasive Flow Machining process provides a theoretical basis and technical support.

Abstract: There were many problems when natural flake graphite was used in gypsum as an absorbing agent, such as absorbing large amount of water, a poor interfacial compatibility and so on. In this paper, polycarboxylate-based water reducer and AES (sodium alcohol ether sulphate) are used to modify graphite-gypsum system. The results show that both agents are effective to improve the properties of gypsum system and the former is best. Compared with the sample without any reagents, polycarboxylate-based water reducer can reduce the water-solid ratio from 1.1 to 0.9, increase the compressive strength from 0.106Mpa to 0.701Mpa and the flexural strength form 0.064Mpa to 0.312Mpa.

Abstract: By scanning the images of bubble structure made through a microscope and measuring characteristic parameters of bubble structure, the paper analyzes the influence of concrete, which is made of different proportion of mineral admixture, on bubble formation and its stability and the influence of bubble characteristics on frost resistance of concrete so as to promote people’s understanding of air-entraining agent application technology.