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This article focuses on research into thermal shock fatigue resistance and oxidation resistance of as-cast ferritic nodular iron. The results show that the number of cycles required to crack nodular iron under the action of thermal stress is significantly higher than that of grey cast iron, and the rate at which cracks spread is lower compared with that of grey cast iron. When graphite is transformed from flakes into nodules, its decreased connectivity impedes the flow of oxygen during oxidization, thereby improving its oxidation resistance.

SAPO-34 molecular sieve was successfully synthesized using calcined-MCM-41 as silica source and morpholine as a template. The influence of MCM-41 content on the synthesis was investigated. The result shows that pure SAPO-34 could be obtained in a wide range of the n (SiO2)/n (Al2O3) ratio in the starting gel. Moreover, increase the n (SiO2)/n (Al2O3) ratio has a negative effect on crystallinity while high silicon incorporates into the framework of SAPO-34. Keywords: MCM-41, SAPO-34, Silicon source

In this work, we reveals the statistical distribution law of 1-3mm coal particle size by MATLAB and the definition and probability distribution function of log-Weibull distribution. In order to get the theoretical probability model of the particle size distribution, we studied the parameter estimation of Weibull, lognormal and log-Weibull distribution though using the maximum likelihood estimation method. The comparison criterion Cc was introduced to evaluate the difference between the theoretical probability density model and the actual experimental data distribution. The results of comparison criterion shows when the particle size has a smaller intervals, log-Weibull distribution is better to predict the experimental data than Weibull distribution and has a smaller change with the different intervals of particle size than others.

Using the steel containing 0.45 percent of carbon as matrix, high carbon ferrochrome as cast-penetrated agent, the steel-based surface composites were fabricated by conventional cast-penetrating process combined with the thermite reaction. The influence of thermite reaction on the microstructures and properties of cast-infiltration layer was researched. The results show that the interfacial bonding is metallurgical fusion between cast-infiltration layer and the matrix under the suitable technological parameters, the thermite reaction during the process of cast-penetrated realizes thermal compensation for liquid metal and improves the mobility of liquid steel by reducing oxidation film of liquid steel surface, consequently increase the thickness of cast-infiltration layer; The ceramic phase of Al2O3 which is generated during the thermite process improves the microhardness of cast-infiltration in a certain extent.

Conditions for changing acceleration and force spindle when the high-speed high-precision camshaft grinding with the action of follow grinding and the constant linear speed grinding，a step-pocket cavity hydrostatic -hydrodynamic bearings is designed to meet this precision camshaft grinding, and the relationship between eccentricity and bearing stiffness, load are analyzed by the method of finite-element analysis with fluid finite element analysis software.

In this paper, the overall structure of a high-speed camshaft grinding carriage and the key components such as electric spindle system and feed system are presented. The model analysis of the electric spindle and grinding carriage box is established to verify the feasibility of the design.

Tension control is a crucial technology for winding control. In the present work, a theoretical analysis and design of tension control used in the winding systems for lithium-ion battery is proposed. Through analyzing the winding process of battery batteries, a speed control curve of the winding motor is designed, with which we can achieve a constant-linear-speed operation of the pole-pieces. Based on the electronic CAM technology, using the approximation method, the constant-linear-speed control curve is obtained. Experimental work is done to study the actual evolution curve of speed for battery pole-pieces. Experimental results show that the rate of speed fluctuation between the maximum speed and the minimum speed reduces from about 10 times to 2 times. It confirms the effectiveness of the application of electronic CAM control strategy in tension control.

To increase the wear resistance of components in slurry pump suffering from serious corrosive abrasion, new super high chromium cast iron (SHCCI) which contains 37wt.% chromium approximately and different carbon content were developed based on the high chromium cast iron with 26wt.% Cr (Cr26). The microstructure of SHCCI was investigated by SEM and XRD. The hardness and impact toughness of SHCCI was tested, and the corrosive wear property of SHCCI was also researched using MCF-30 type erosion abrasion tester under H3PO4 medium condition. The results show that the microstructure of SHCCI is composed of carbide of M7C3+M23C6, martensite and retained austenite. With the increase of carbon content, the hardness of SHCCI first increases and then decreases, the toughness increases, and the corrosive wear property decreases. The relative wear resistance of SHCCI is obviously superior to that of Cr26 cast iron, and the maximal relative wear resistance of SHCCI is three times higher than that of Cr26 cast iron.

In recent years, high chromium cast irons have been widely applied in many fields because they have high hardness and abrasion resistance. However, high chromium cast irons are also expensive because much alloying elements, such as chromium, molybdenum and nickel, are added into them. In order to resolve above question, a new abrasion-resistant steel with high boron content was developed in this paper. The new high boron steel, with 0.6%~0.8%B and 0.65% C, was prepared using sand casting method. The microstructure and mechanical properties were researched. The results show that the solidification microstructure of as-cast high boron steel consists of boride (FeB) and matrix composed of pearlite, ferrite, and bainite. And the borides distributes along grain boundary in the form of network. After quenching at 980°C and tempering at 250°C, the FeB transforms to Fe2B, and the matrix transforms lath martensite. The hardness of as-cast high boron steel is 43HRC, and its impact toughness is 5J/cm2. After heat treatment, they increase to 56 HRC and 7J/cm2, respectively, approximating that of high chromium cast irons. The new high boron cast steel have a potential in stead of high chromium cast irons

To enhance the wear resistance of molybdenum alloys, Mo-based composites reinforced by Al2O3 ceramic particles were developed. Using Al(NO3)3 aqueous solution and MoO3 as raw materials, the Molybdenum powders mixed with Al2O3 particles were prepared by liquid-solid incorporation, drying, pyrolysis of Al(NO3)3 and deoxidation of MoO3 by H2. And then the Mo-based composites with 3-10vol.% Alumina were prepared by compaction and sintering at 1840°C. The morphology of the Molybdenum powder and microstructure of the composites were analyzed by SEM and XRD. The micro-hardness, density and wear property of composites were researched. The results showed that α-Al2O3 ceramic particles and Molybdenum matrix compose the composites. With the increase of Alumina content, the molybdenum powders become fine and rule, the grains of composites become fine, the microhardness of Molybdenum matrix increases, and the density first increases and then decreases. The friction coefficient of composite is scarcely affected by the alumina content. While the wear weight of the composite decrease with the increase of Alumina content. There are obvious plow furrow and abrasive dust on the worn surface, showing the abrasive wear characterization.

In this paper Finite Element Method (FEM) was used to study the indentation behavior of aluminum alloy 2A12 with nonmetallic inclusions. Indentation elastic-plastic tests and indentation creep tests were simulated with a cylindrical indenter to analyze the influence of the inclusion size and the inclusion depth. FEM results indicate that the existence of inclusions will have certain influence on the indentation behavior, and when the inclusion size is close to the indenter size, the influence is obvious. For the indentation method, the conclusions can provide some useful information in the project application.

A reliability-based multidisciplinary design optimization (RBMDO) frame work for Centrifugal compressor was presented. Multidisciplinary feasible method was used to decouple the multidisciplinary analysis and the fourth moment method for reliability analysis was recommended systematically. Based on the approximation, the RBMDO framework was finished. The case study shows that optimization efforts could improve obviously the performance of centrifugal compressor under the requirements of reliability. This framework could make the design reach the best performance with a good reliability. It indicates that the proposed optimization method is available and feasible for the engineering application.

A new wear resistance material named the hypoeutectic high carbon Fe-B cast steel with fine hard carbides dispersive distributed in the matrix have been investigated. The results show that the solidified structures of high carbon Fe-B steel consist of ferrite, pearlite and boride, and borides were distributed along grain boundary in interconnected network. After heat treatment, the metallic matrix changes into martensite and retained austenite. The eutectic borides are appeared to be less continuous network and isolated particles. The increasing of the quenching temperature leads to the improvement of hardness. Quenching at 980°C, impact toughness is increased with the increasing of the tempering temperature. The optimum heat treatment is quenching at 980°C(oil cooling) and tempering at 330°C(air cooling). The wear resistance of modified high carbon Fe-B cast steel is corresponding to Cr26 alloy. The impact wear mechanism is mainly plastic deformation and fatigue spalling.

To improve the wear resistance of high chromium white cast iron under severe abrasive conditions, a composites layer was designed for wear surface, which were locally reinforced with WC particles. And the local composites were successfully fabricated by optimized centrifugal casting process. Then the interface between WC and iron matrix was analyzed with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). And three body wear tests were carried out on a self-made rig to investigate the wear resistance of the composites. For comparison, the wear tests of high chromium white cast iron were also carried out under the same conditions. The results show that: There are no defects such as inclusion, crack, gas pore and so on in the obtained composites layer, which with a uniform thickness of 10 mm. WC particles are homogeneously distributed in the composites layer and tightly bonded with the iron matrix. The WC particles are partially dissolved in the iron matrix during centrifugal casting. The elements W, C and Fe react to form new carbides such as Fe3W3C or M23C6, which precipitate around former WC particles during subsequent solidification. So the interface between WC particles and the iron matrix is a strong metallurgical bonding. WC particles in the composites layer can effectively resist cutting by the abrasive, and then protect the matrix. The wear resistance of the composites layer is 7.23 times of that of high chromium cast iron.