Advanced Materials Research Vols. 1004-1005

Abstract: The fracture of a carbon steel pneumatic control valve rod used for Nuclear Power Plants was analyzed in terms of the microstructure, inclusions and fractogragh by means of tensile test, charpy V-Notch impact test, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The results indicated that the fracture of the rod is induced by the unqualified chemical composition: a large number of inclusions which distribute in grain boundaries reduce the material plasticity and toughness, and eventually cause fracture.

Abstract: Influence of relative clearance to hole quality is investigated by numerical simulation and experiment. The numerical simulation in punching process of sheet metal is conducted by using ANSYS/LS-DYNA.The relative clearances in two sizes are selected to investigate the difference of holes cross section. Influence regularity of the relative clearance to hole quality is obtained by experimental investigation.

Abstract: Hydroforming has many advantages over other processes, especially when runs are small and shapes are complex. The hydroforming process of automobile front transom was simulated by FEM, which is based on elastic-plastic finite element method and BT shell element theory. The effect of forming process parameters such as internal pressure loading path and initial tube size were simulated and discussed. The simulation results indicated that suitable initial tube size and loading path can observably improve the distribution of the thickness and forming limit of the tube. And for the front transom, tube size Ø55mm and bilinear loading path are the best process parameters.

Abstract: Bonded NdFeB is a high performance composite magnetic materials which developed in recent years. Compression molding is the most important making method of bonded NdFeB magnets. The Characteristics of bonded NdFeB magnets are introduced. Based on test, research and lot production practice, the important effects of mould structure, press structure and compression molding actions on magnets’ quality are analyzed, The key techniques that controlling the quality of bonded NdFeB magnets are summarized.

Abstract: Because difference of formation model affects the potential distribution on the metal casing, the resistivity logging response can be obtained through casing by measuring the potentials on the metal casing. In fact, the logging responses are the comprehension effects of complex formation with cement sheath and metal casing, so that in the coefficients of transmission line equation (TLE), we should consider the effects of formation with cement sheath model in radial-direction. In the following, for the formation with cement sheath taking on eight-layer in axial-direction, and step in radial-direction, the resistivity logging responses through casing are researched and discussed, and given the recurrence formula with cement sheath to compute potential. Draw the curve of the resistivity logging response through casing of eight-layer formations with cement sheath. The conductivity of formation is computed is very approximating to that of formation with cement sheath model. The computing examples also show that this method has a fast computing speed (the run time of computing example is less than 1s). For analysis the logging response of eight-layers and block formations with cement sheath, and the design of logging instruments, the research is important significance and useful.

Abstract: Through analyzing and comparing the ultrasonic drilling and general drilling, exported from cutting dosage and burr , etc, using the ultrasonic vibration drilling device to carry out the TC4 titanium alloy micro-hole drilling test. The ultrasonic vibration drilling more suitable than general drilling for the processing of Titanium Alloy, and solve Φ 2.0 x 20 TC4 Titanium Alloy drilling of small diameter deep hole problem. Fully embodies the advantages of ultrasonic vibration drilling.

Abstract: Wet centrifugal separation process is used to purify diatomite by analyzing the properties of diatomite raw ore in Linjiang city, Jilin province. Experimental results determine the affecting sorting important indicators, including scrubbing agent and dosage, sieving mesh, centrifugal separation. The concentration of SiO₂ in the final diatomite is 86.76%, reaching primary soil standard. Compared with gravity sedimentation purification process, new technology method saves much time and achieves the ideal separation effect.

Abstract: Squitter pulse argon-arc welding technology due to its unique way of energy output, has the quick repairing speed, low heat input and high bonding strength on the repairing process. The results of balance shaft parts after repairing by squitter pulse argon-arc welding technology showed that there was no significant micro–pore but closed combination between the substrate and repaired layer. The width of HAZ was 350μm, the average hardness of repaired layer was 420HV, and the wear-resisting property was improved about 36.4%, compared to the substrate. The squitter pulse argon-arc welding technology is a simple, reliable new repair techniques.

Abstract: Integration of smart materials such as field-responsive fluid, i.e. Electro-rheological (ER) , magneto-rheological (MR) and shear thickening fluids (STFs), into armor protective materials, may probably solve the problem between its portability and protective performance. The wide applications of three fluids are described in brief in this paper, and research developments (especially STFs’ in detail) of armor protective materials strengthened by utilizing three fluids or chemical reaction material are summarized. Analysises are made of the questions faced by these composites researches. The foreground is talked about in the end.

Abstract: Failure causes on a condensate pump shaft were discussed by means of macroscopic observation, chemical composition analysis, metallurgical microstructure inspection, mechanical property tests and stress analysis. The experimental results showed that the improper material with disqualified chemical composition, improper microstructure and poor mechanical properties acted as inherent factor. In addition, structure design that led to stress concentration contributed to the failure as external factor. Finally, fatigue fracture happened at the reduce section of the pump shaft.