Papers by Author: Chang Zhi Jia

Abstract: The temperature of the gun chamber interior wall is an important parameter for the research of the gun barrel life, and the heat transfer by conduction rule between the barrel interior and exterior wall can be ensured by measurement extrapolation method or method of finite element. By choosing a suitably, designed a measurement device of the gun barrel temperature which can be used to measure and memorize the exterior wall temperature of the gun barrel.

Abstract: The barrel life is decided by explosive payload, tempreture, firing interval, ammunition type and other factors. Thus the zone charge’s auto-recognition is the first question to realize the automatic prediction technology of the barrel life. The zone charge’s recognition technology was proposed based on BP Network. The theory support could be provided by the technology to realize the zone charge’s auto-recognition.

Abstract: A new experimental project was adopted for the special hot-work of pure Cu, which used the execrable condition of high-temperature and high-pressure environment in bore of artillery. Specimen of Cu was prepared from rotating band of sand projectile which had been shot out. Microstructure of Cu after instantaneous extrusion and high speed friction were observed by scanning electron microscopy (SEM). Severe plastic deformation (SPD) and recrystallization phenomena were researched. The analysis results are as follows. At the beginning of SPD, under the instantaneous compression, the surface layer of metal became fibrous tissue with the phenomena of work-hardening. Many oblique strip grains appeared between equiaxed grains and fibrous tissue. With the continuous plastic deformation, temperature of metal improved rapidly under the high speed friction. Recrystallization occurred on the outermost part of fibrous tissue due to heating, so sub-grains gradually became homogeneous equiaxed grains. In addition, SPD had little effect to the inner structure, which is full of equiaxed grains still. All above work could support the research of microstructure of Cu on certain extreme particular environment.

Abstract: As a special hot-work progress, artillery shooting test was put in practice, and rotating band specimen of Cu-4 Mass%Zn alloy was prepared. The mesostructure and microstructure evolution of the alloy under instantaneous extrusion and high speed friction were observed by optical microscopy (OM) and scanning electron microscopy (SEM). Severe plastic deformation (SPD) and dynamic recrystallization phenomena were researched. The analysis results are as follows. At the beginning of SPD, under the instantaneous compression, the surface layer of alloy became fibrous tissue with the phenomena of work-hardening. With the plastic deformation continue, temperature of alloy arising rapidly under the high speed friction. Recrystallization occurs within the outermost part of fibrous tissue due to heating, so subgrains gradually become homogeneous equiaxed grains. In addition, SPD has little effect on the inner tissue, which is full of equiaxed grains still. Between equiaxed grains and fibrous tissue, there are many oblique strip grains which formed by radial extrusion stress , tangential slip stress and axial sliding stress .