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To investigate the deformation behavior of Mg-X(X=Zn, Y) binary solid solution, the strain-stress curve of crystal cell along [0001] for Mg-1.85at.%X(X=Zn, Y) alloy were simulated using first-principles calculations in this study. The simulation presents directly the critical resolved shear stress for pyramidal plane slip systems for Mg-1.85at.%X(X=Zn, Y) alloy. The results show that the minimum critical resolved shear stress (CRSS) of Mg, Mg-1.85at. %Zn and Mg-1.85at. %Y for pyramidal plane slip systems is 2.24, 2.72, 2.96 GPa respectively.

Mg-5Y-3Ni-0.2Zr (wt. %) and Mg-5Y-3Zn-0.2Zr (wt. %) alloys with LPSO structure have been designed and fabricated. The microstructure and mechanical property of both the extruded alloys have been comparatively studied. The results showed that the alloy with enough Ni exhibited higher elongation due to the high volume fraction of LPSO structure with excellent compatible deformation capability. The presence of deformation kinks with high kink angle demonstrated the capability of LPSO structure to accommodate the deformation, which could greatly increase the ductility and the toughness of the alloy.

In order to reduce the human factor risk in drilling process, the author analyzed the primary reason of human factor risk in drilling process, selected twelve risk control measures and toke Delphi method to quantify the human factor risk mitigation capacity resulting from the selected risk control measures. The results shows that the human risk control measures exist in three tiers of effectiveness that with each tier being separated by nearly an order of magnitude, and the types of most risk mitigation are risk codes such as injury by machine, fall from height, contact with harmful material. And the most minimally risk mitigation ones are muscle strain, fire explosion and other types. Finally these data, which will be valuable for drilling companies to strategically allocate limited resources to their safety management plan, can evaluate the expected effectiveness resulting from risk control measures.

In order to quantifying human factor initial risk level in drilling process, the types of work activities involved in drilling were identified, the major accident risk types of human errors were selected, the probability and severity levels of risks associated with each activity were quantified, and the human factor risk level of major work activities involved in drilling process were calculated. Quantitative results show that the relatively highest risk types during drilling process are struck by object (risk value is 3.9171 S/w-h), injury by machine (risk value is 2.8916 S/w-h), overexertion (risk value is 1.5091 S/w-h), etc. Contrarily, the relatively lowest risk types are exposure to harmful substances or environments (0.7379 S/w-h), fire and explosion (0.2750S/w-h), and othersi0.2261 S/w-h), etc. The relatively highest risk activities are associated with penetration drilling (risk value is 2.7475S/w-h), trip in and out (risk value is 2.0206 S/w-h), and hoisting and lifting operation (risk value is 1.7064 S/w-h), etc. Contrarily, the relatively lowest risk activities are auxiliary operations (risk value is 0.3706S/w-h), well logging and mud logging (risk value is 0.2059 S/w-h), equipment inspection and maintenance (risk value is 0.1510 S/w-h), etc. The total risk value of all main drilling activities is 11.3947 S/w-h.

Cycle capacities of Amorphous Mg-Ni alloys declined so fast therefore they can’t be used practically. In this paper，the influence of adding Ti on the discharge capacity and cycle stability of the alloys were investigated. Amorphous Mg1-xTixNi (x=0, 0.1, 0.2, 0.3) alloy powder was prepared successfully by mechanical alloying (MA). X-ray diffraction (XRD) results show that MgNi alloy formed completely amorphous phase after ball milling with 15h. But for Mg1-xTixNi (x=0.1, 0.2, 0.3) alloy, it took 23h. It can be concluded that Ti partial substituting Mg would decrease the amorphous phase forming ability of Mg-Ni based alloy. Compared with amorphous MgNi alloy, the maximal discharge capacities of Mg1-xTixNi (x=0.1, 0.2, 0.3) alloy were decreased slightly, but the cycle stabilities were significantly enhanced. Mg0.9Ti0.1Ni alloy showed the largest discharge capacity and the best cycle stability.

Calculated phase diagram reveals important phase details for a new type muti-component magnesium alloy. Isothermal sections at 25°C of Mg-Ca-Sr, , Mg-2.74Al-Ca-Sr, Mg-2.74Al-0.79Zn-Ca-Sr system in the Mg-rich region were calculated using CALPHAD method, Thermo-Calc software and Mg-Al-Zn-Ca-Sr quinary database. The equilibrium phase composition in the Mg-rich region was analyzed. The equilibrium phases and solidification process of Mg-2.74Al-0.79Zn-0.68Ca-0.03Sr quinary alloy was calculated. The calculation results were consistent with the experimental results of SEM-EDX analysis and DSC spectrum. The solidification process of Mg-2.74Al-0.79Zn-0.68Ca-0.03Sr quinary alloy is as follow : α-Mg precipitates at 621°C, secondary phase C15-Al2(Ca, Sr) and Gamma-Mg17Al12 precipitate at around 520°C and 160°C in sequence, A4B-(Al4Ca,Al4Sr) may precipitate at around 460°C.

The effects of yttrium addition on microstructure and mechanical properties of extruded Mg-Zn-Y-Zr magnesium alloys were investigated by using optical microscope(OM), X-ray diffraction(XRD) and scanning electron microscope(SEM) et al. It was shown that the addition of yttrium resulted in the formation of the new phase, Mg3Zn3Y2, which distributed both on the grain boundaries and inside the grains. With the increasing of Y content, the amount of Mg3Zn3Y2 phase increases and the size becomes uniform. Grain refinement was found especially with 5.92%Y addition and a certain amount of coarse grains were formatted in the alloy with 3.95% Y addition, which led to the decline of the mechanical properties. The yield strength of the Mg-Zn-Y-Zr alloys was improved with the addition of Y, but the tensile strength was not changed obviously.

Metal rubber material is a new type of elastic and porous material which develops from metal materials. The macro-structure of metal rubber is reticular just as high polymer, made up of fine metal wires. In this paper, the testing equipment which can test micro-motion of metal rubber is designed and the compressive force-displacement curve along molding of metal rubber has gain. The cure along molding of metal rubber has three different characteristic stages. In different characteristic stages, the deformation of metal rubber material has different micro physical mechanism. The micro physical mechanism of different deformation periods is summarized by the micro analyses of three different characteristic curve stages and the study of metal rubber molding technology. Based on the manufacture technology and molding process, the spring wires in metal rubber material have contacted adequately after molding. The micro physical mechanism of metal rubber material in this stage is produced by blank tear combination deformation in linear elastic of spring wires. Because of the deformation stage is very little; the stiffness of metal rubber material is represented linear characteristic in this stage. The contacted points of spring wires are slide along with deformation increasing. The stiffness of metal rubber material is reduced after early linear deformation stage. The compressive force-displacement curve represents soft characteristic stage in macro- expression. When the most contacted points of spring wires are slide along with deformation increasing, the stiffness of metal rubber material is rapid rise. The exponential reinforcement stage is caused by the strongly constraints among spring wires. The micro physical mechanism can explain the different characteristic stages of metal rubber material on compressive performance.

In this paper，the influence of adding Al on the discharge capacity and cycle stability of amorphous MgNi-based hydrogen storage alloys were investigated. Amorphous Mg1-xAlxNi (x=0, 0.1, 0.2, 0.3) alloy powder was prepared successfully by mechanical alloying (MA). X-ray diffraction (XRD) results show that after ball milling with 15h, MgNi alloy formed completely amorphous phase. But for Mg1-xAlxNi (x=0.1, 0.2, 0.3) alloy, it took 30h. It can be concluded that Al partial substituting Mg would decrease the amorphous phase forming ability of Mg-Ni Based Alloy. The discharge capacities and cycle stabilities of these alloys were tested. Compared with amorphous MgNi alloy, the discharge capacities of Mg1-xAlxNi (x=0.1, 0.2, 0.3) alloy were decreased slightly, but the cycle stabilities were significantly enhanced. Mg0.9Al0.1Ni alloy showed the largest discharge capacity and Mg0.8Al0.2Ni alloy showed the best cycle stability. Over all, ternary Mg0.8Al0.1Ni alloy showed the best synthesis properties.

In order to make full use of magnesium alloy resources under the environment of the network, an integrated magnesium alloy database system prototype has been developed, which consists of five modules, including database utilizing, files management, report printing, data inquiry and system utilities. This system gives more conveniences to user’s work by adopting three-tier architecture and using advanced technologies such as ASP (Active Server Pages). The user who only owns a global browser can conveniently use this database system without pre-installing any other application softwares. This database system prototype is a powerful tool to cut down the cost and time for developing new magnesium alloys.

The influence of Al-10.5%Sr master alloy, which is much cheaper than Mg-Sr master alloys, on the as-cast microstructure of the AZ31 alloy was investigated. The research results revealed that the Al-10.5%Sr master alloy produced obvious modification of the as-cast microstructure of the AZ31 alloy, and the modification efficiency increased with the holding time from 0min to 60min and the amount of Sr from 0.01% to 0.1%. Moreover, the results also showed that the Al-10.5%Sr master alloys of different states had different modification efficiency on the as-cast microstructure of the AZ31 alloy. The Al-10.5%Sr master alloys in extrusion deformation state and rapid solidification state had better modification efficiency than the Al-10.5%Sr master alloys received and in heat treatment state, which could be related to the microstructure of the Al-10.5%Sr master alloys with different states.

Alloy phases in the as-aged (T6) ZK60 magnesium alloy were investigated. More attentions were paid to types and morphologies of main alloy phases in the as-aged ZK60 magnesium alloy. The experimental results indicated that there was an abundant flower-shaped segregation in the solution-treated ZK60 magnesium alloy. A small quantity of undissolved compounds, MgZn2, was also found. They distributed irregularly in the form of similar parallelogram, with a dimension of 200nm~500nm and not sensitive to heat-treatment. Mg2Zn3 was found to be a main secondary compound in the as-aged ZK60 alloy, which precipitated during aging. Another precipitation phase, MgZn, in the as-aged ZK60 magnesium alloy was also found in the form of long and thin rods with a dimension of 500nm.

Morphologies of precipitation phases along grain boundaries of the as-cast Mg-6.0Zn-0.45Zr, Mg-6.0Zn-1.2Y and Mg-6.0Zn-0.6Zr-1.0Y alloys were investigated. The experimental results indicated that the main precipitation phase along grain boundary of the as-cast Mg-6.0Zn-0.45Zr was a Mg-Zn binary compound. There were two kinds of precipitation phases along grain boundaries for Mg-6.0Zn-1.2Y and Mg-6.0Zn-0.6Zr-1.0Y alloys. One grew at triangular grain boundary, which was fish-bone -like in shape and a Mg-Zn binary compound. The other distributed mainly around the grain, which was net-like in shape and a Mg-Zn-Y ternary compound. In addition, there were lots of granular phases, extending to the interior of the grain, at the rim of grain boundary phases. Y was found to affect obviously morphology of precipitation phases along grain boundary of the as-cast Mg-Zn-Zr (ZK60) alloys.

A model was developed for the analysis and prediction of correlation between composition and mechanical properties of Mg-Al-Zn (AZ) magnesium alloys by applying artificial neural network (ANN). The input parameters of the neural network (NN) are alloy composition. The outputs of the NN model are important mechanical properties, including ultimate tensile strength, tensile yield strength and elongation. The model is based on multilayer feedforward neural network. The NN was trained with comprehensive data set collected from domestic and foreign literature. A very good performance of the neural network was achieved. The model can be used for the simulation and prediction of mechanical properties of AZ system magnesium alloys as functions of composition.

Due to its intrinsically poor repair potential, injuries to articular cartilage do not heal and clinical intervention is required. Osteochondral grafts may improve healing while promoting integration with host tissue. We report here the development of an osteochondral graft based on a hybrid of a hyrogel and a polymer-bioactive glass composite (PLAGA-BG) microsphere scaffold. This novel osteochondral construct consists of three regions: gel-only, gel/composite interface, and a composite-only-region. The three phases differ in calcium phospate (Ca-P) or BG content. The objective of the current study is to investigate the effects of scaffold composition on chondrocyte response, and to evaluate the effects of co-culture on osteoblasts and chondrocyte growh and differentiation on the hybrid scaffold. The PLAGA-BG microsphere scaffold supported the growth of chondrocytes and initial results indicate that in the presence of BG, chondrocyte-mediated mineralization may be stimulated. Co-culture of osteoblasts and chondrocytes on the multi-phased scaffold with varied Ca-P content facilitated the formation of multiple matrix zones: a GAGrich chondrocyte region, an interfacial matrix rich in GAG+collagen, and a mineralized collagen matrix with osteoblasts. In summary, chondrocyte response has been optimized as a function of scaffold composition and the novel osteochondral graft has the potential to support the simultaneous formation of multiple types of tissue in vitro.

Mechanical activation has been found to be a very effective method of inducing reaction. In this paper, a mixture of ilmenite and graphite with a molar ratio of 1 to 3∼4 was ball milled at room temperature and subsequently annealed. The enhanced carbothermic reactions were monitored by thermogravimetric analysis and X-ray diffraction analysis. A series of reduction reactions occurs with a higher reaction rate in a temperature range lower than that without pre-milling. A longer milling time leaded to a lower reaction temperature and less intermediate phases. When the milled powder was heated in a tube furnace to a temperature range between 1300 °C and 1400 °C for 2∼6 hours under a cheap mixed gas containing nitrogen, the composite powder of iron and Ti(C,N) without intermediate phases was achieved.