The lapping trace distribution on ball surface is one of the key factors during the lapping process, which can affect the sphericity of lapping. The Rotated Dual-Plates lapping mode (RDP lapping mode) can achieve better uniformity of lapping trace distribution on precision ball surface, which ensure the results of forming sphere by lapping. Combining with the basic principle of RDP lapping mode, as well as the analysis of the kinematics of the RDP lapping method, this paper puts forward a basic rule about the material removal at the contact point between the ball and the plate with the material removal rate equation of bearing steel, and the improvement of the sphericity which can be simulated, and is defined as the lapping uniformity according to basic rule equation. The influence caused by the lapping pressure and the speed of the plates are considered in the simulation, the surface of ball is triangle grid divided. The uniformity of lapping is evaluated at different speed ratio, and eventually a better curve of the speed ratio can be got, so the lapping uniformity during the RDP lapping mode can finally be accurately evaluated.

Carbon-fiber-reinforced polymer (CFRP) has been widely used in aerospace structures for its high strength to weight ratio and high stiffness to weight ratio. However, current pyrotechnic separation devices are mainly made of metal materials, the cutting research on CFRP composites is limited, and the effect of weakening groove on cutting results of composites is unclear under the action of shaped charge jet. In this paper, there firstly established a three-dimensional model of explosive cutting of CFRP composites by nonlinear finite element analysis (FEA), and based on the separation time, delamination, and kinetic energy of the laminate, the influence of weakening grooves on cutting results to the laminate is discussed. The results show that, in contrast to laminates with weakening grooves, laminates without weakening grooves increase the delamination of laminates. At the same time, here, we carried out the explosive cutting test on CFRP composites to verify the rationality of the simulation model. In addition, in order to obtain a better model under the action of shaped charge jet, we optimized the width and height of weakening groove by simulation calculation. Therefore, it proves that this study can guide the application of CFRP composites subjected to shaped charge jet in aerospace separation engineering.

To study the lapping process and sphere-shaping mechanism of WC-Co cemented carbide ball under eccentric dual-rotating (EDR) V-groove lapping mode, the research center designs EDR V-groove lapping machine. This paper analyses sphericity of WC-Co cemented carbide balls after the lapping. During the lapping process, the diameter variation is measured every one hour. The diameter of ball is usually reduced 0.05mm every hour, which is more than the dual rotating plates(DRP) lapping mode, and the experiment is totally done 9 hours, the error of sphericity can be controlled around 0.005mm in the last, so the EDR V-groove lapping mode is more suitable for lapping of the WC-Co cemented carbide ball in roughness and semi-finishing process. In order to compare the material removal rate between DRP lapping mode and EDR V-groove lapping mode, the balls are also lapped under DRP lapping mode.

In order to get high precision balls used in oil exactor, Eccentric dual-rotating (EDR) V-groove lapping mode and Rotated dual-plates (RDP) lapping mode are applied for the batch processing of WC-Co cemented carbide balls of Φ35mm. After comparing two innovated modes, firstly EDR V-groove lapping mode is used in rough lapping stage for high efficiency, and then semi-finishing lapping stage, finishing lapping stage and polishing stage are carried out by RDP lapping mode. Through changing the processing parameters legitimately, including abrasive grain, adjustable rotating velocity and load, the rational course and parameters are defined, and WC-Co cemented carbide balls of Φ35mm satisfy the end products’ demand which means the sphericity is less than 1μm and the roughness of surface (Ra) is better than 50nm, so these balls can be applied in one-way hydraulic value used in oil exactor.

In this paper, the batch processing of Φ35mm WC-Co cemented carbide balls used in one-way value is studied by rotated dual-plates (RDP) lapping machine. On the basis of this innovated equipment, the processing parameters, including abrasive grain, rotating velocity and load, are changed legitimately in experiment. The experimental results show that the abrasive grain is used from big to small, while the rotating velocity and load are gradually reduced in order to improve the uniformity of lapping trace distribution on the ball surface in batch processing. Finally the rational course and parameters are defined, these WC-Co cemented carbide balls satisfy the products’ final demand which means the sphericity error (Rnd) is less than 1μm and the roughness of surface (Ra) is better than 50nm. Because of the feasibility, the precision of final WC-Co cemented carbide balls improves and can be applied in one-way value used in oil exactor.