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A pneumatic wheel tool with reinforced aramid fiber is presented to finish irregular freeform surface with high hardness. Aramid fiber mainly is selected as a filler to achieve multi-dimension net distribution in polymer. In this case, the wheel can keep the outer abrasive particles more stable and decrease scratch damages of surface in the high-speed machining process. Based on the Halpin-Tsai formula, the orientation coefficient is brought in for the establishment of an elastic modulus prediction model of a fiber-reinforced pneumatic wheel. By ANSYS simulation, rules of stress and strain of pneumatic wheel with different volume ratios of fiber are given. It has been proved out that the fiber-reinforced method can overcome the defect of inner rubber deformation in the contact process. By mixed refining method, pneumatic wheels reinforced by aramid fiber are achieved. Multi-dimension net distribution of aramid fiber–reinforced polymer is observed in a microscopic view. Elastic modulus–predicted model is confirmed by drawing experiments. After that, aramid fiber–reinforced pneumatic wheel machining experiments are carried out. Results show that the fiber-reinforced method can improve surface roughness efficiently in the pneumatic wheel machining process and decrease scratch damages of the surface. [ABSTRACT FROM AUTHOR]

For improvement of finishing effect to the laser hardening mold's free-form surface with high hardness, double-layer elastic mechanics theory of pneumatic wheel based with softness consolidation abrasives (SCA) is analyzed. Under the annular stress around, ratio coefficient m of modulus of elasticity of abrasive layer to modulus of rubber layer and ratio coefficient n of thickness of abrasive layer to radius of stress have been bought in for establishing machining force model and deformation formula of double-layer elastic wheel. After that, a double-layer elastic model of the wheel has been established by ANSYS and the machining process has been simulated. Stress distribution and deformation rule are given by simulation. In the experiments, we use fiber to reinforce inner rubber layer and take binder to hold on abrasive particles. Microscopic analysis demonstrates that pneumatic wheel accords with the situation of double-layer elastic mechanic theory. Moreover, machining platform is established and empirical results show that pneumatic wheel can finish laser hardening mold's free-form surface efficiently. And conclusion shows pneumatic wheel with lower factor n can help to decrease R when it faces with concave surface and pneumatic wheel with higher factor n can improve machining efficiency to convex surface. [ABSTRACT FROM AUTHOR]

Pneumatic wheel based on softness consolidation abrasives (SCA) is presented as a key machining tool mainly for the improvement of finishing efficiency to free-form surface of laser-hardened molds. In this case, though its softness fits for machining to free-form surface, it cannot keep all abrasives within bounds strictly, but it makes abrasives experience creep deformation, which always leads to unstable machining characteristics. For research on the working rule of SCA, dynamic characteristics of abrasives need to be investigated. Firstly, soft ball model is brought into analysis of the normal and shear contact forces between two particles. By introducing damping coefficient, formulas on displacement and velocity of SCA are given for theory analysis of creep deformation. After that, force chains are established by simulation, which proves that SCA possesses more cutting force than free abrasives. At the same time, creep deformation of SCA is confirmed in accordance with the analysis of velocity of the single particle. Subsequently, combined with the modified Preston formula, comparative machining tests on material removal are carried on a laser-hardened free-form surface. Experimental results show that material removal rate of SCA is higher than that of free abrasive by approximately 34.35 %. Moreover, abrasive size is discussed as a key parameter respectively according to consolidation effects and surface roughness. The final conclusion is that SCA is certified to improve finishing efficiency for laser-hardened surfaces as well as suitable for machining free-form surfaces. [ABSTRACT FROM AUTHOR]