Papers by Author: Zhi Wang

Abstract: According to the gear meshing theory, the tooth surface equation of orthogonal face gear is derived and the mathematical model is established. Also the model was provided for simulating the bevel gear transmission system concerning the time variant stiffness and face gears errors under static load and cyclic loads. Through the model the computerized analysis of speed, angle and acceleration of gear real tooth surface could be accomplished. Rattle as discussed under condition of different static loads and the constant cyclic loads.

Abstract: According to the simulation of the face gear in UG, the research established the model of face gear. A perfect model that can be used in ANSYS was obtained through reserve modeling. The blending situation of three models of face gear was analyzed in ANSYS. The blending stresses distribution area and the influence on gear teeth bending stresses of different parameters i.e. modulus, width and number of teeth were discussed. And the discipline of the bending stresses under these parameters was got. It provides a new analysis method to research the characteristics of stress of face gear.

Abstract: Based on analyzing the defects of the usual equivalent conversion methods,the paper presents a new equivalent conversion method for mesh stiffness calculation of straight bevel gears of the small teeth number and diameter. By means of comparison among the different calculation methods,the conclusions can be obtained as follow:The straight bevel gear’s mesh stiffness value calculated by the new equivalent conversion method and Yishikawa formulae improved is more enhanced obviously than one calculated by the usual equivalent conversion methods and Yishikawa formulae ,and its change trend is closer to the numerical calculation value than the change trend of the straight bevel gear’s mesh stiffness value calculated by the usual equivalent conversion methods and Yishikawa formulae.

Abstract: The formation and existence of burrs is one of the common phenomena in machining. It affects directly machining accuracy and parts quality. Network database system for metal cutting burr is developed using ASP.NET platform. The management of metal cutting burr data, inquiry and prediction of cutting burrs types and sizes, optimization of cutting conditions for controlling burr forming which based on the reasoning method of BP neural networks are realized. The development and realization of network database of metal cutting burr provide a convenient way for data transmission between multi-workshop and across regions, promote the development of burr controlling technology and modern manufacture technology.

Abstract: Grind-hardening was done on 65Mn steel with a conventional surface grinder and a corundum-grinding wheel. Research was conducted to probe into microstructures and properties of the hardened layer under varied depth of cut and cooling conditions. Results show that the hardened layer does not change noticeably in their martensitic structures and micro-hardness, which is ranged between 810-870HV. When the depth of cut increases or the dry grinding technique is adopted, the hardened layer becomes thicker accordingly. Under the condition of dry grinding with the depth of cut 1.0mm, the hardened layer depth reaches 2.0mm. It can find applications in grinding and metal surface modification field.

Abstract: The addition of manganese into Nd9Fe85-xMnxB6（X=0,0.5,1） was found to enhance the magnetic properties of a -Fe/Nd2Fe14B magnets. After optimal annealed, the coercivity and remanence ratio increased from 0.34MA/m to 0.4MA/m and from 0.70 to 0.72, respectively, for the increase of x from 0 to 1. The XRD patterns indicated the addition of manganese could promote crystallization of as-spun samples. Moreover, the XRD spectra showed almost same grain sizes obtained for the optimal annealed samples. Thermomagnetic analysis (TMA) measurement indicated that the doping of Mn reduces the Tc of the Nd2Fe14B phase and raises that of a-Fe phase in the system. It is believed the exchange coupling between the Nd2Fe14B phase and a-Fe phase was partly changed by Mn addition, which is the reason for the enhanced magnetic properties and the change of Tc.

Abstract: The precipitation behavior during ageing treatment of a single crystal nickel-base superalloy was investigated by SEM and TEM. The results showed that tetragonal needle-like σ phase and blocky -W phase precipitated during low temperature ageing treatment after this testing alloy was completely solution heat treated. σ and -W phases robbed of solid solution strengthening alloying element W、Mo in the matrix and degraded high temperature creep rupture property severely. The creep curve of the crystal tested at 1010 °C and 248 MPa exhibited that the steady state creep rate ε was as high as 9.46 × 10-3/h. The creep-rupture life was only 25 hours. -W phase was not formed by decrease of W content properly. A relatively low level of Co could inhibit σ phase precipitation and improve microstructural stability.

Abstract: Investigation of γ -channel widening behavior in a nickel-base single crystal superalloy during uniaxial tensile creep tests was carried out. Scanning electron microscopy (SEM) was adopted to reveal the microstructural evolution of γ -channel and the dimension of γ -channel. It was found that different tests condition such as temperature, time and stress in tensile creep tests all influenced the γ -channel widening behavior, and a parabolic rate law governs the mean increase value of γ -channel width. The stress and temperature enhanced the γ -channel widening. The γ -channel widening was the result of directionally diffusion of multiatom.