EFFECT OF TARGET SHAPE ON IMPACT FRAC-TURE CHARACTERISTICS OF SINGLE PARTICLE OF NYLON 6
1981 Volume 14 Issue 2 Pages 142-148
Details
1981 Volume 14 Issue 2 Pages 142-148
This paper is concerned with the fracture characteristics of a spherical particle of nylon 6 when the particle, accelerated by an air gun, is impacted on various wedge-shaped targets having wedge angles of 180°, 150°, 120v, 90°, 70°, 50°, and 30°, respectively.
The impact velocity and rebound velocity, deformation, and impact force of a particle are measured and an instantaneous photograph of fracture is also taken.
The maximum impact force measured at the impact velocity where the impact particle begins to be fractured can be formulated as a power law with respect to the wedge angle of the wedge target, and the value of the exponent is about 2.3 over the ranges of wedge angle from 30° to 180°, that is, the flat target.
It is found that there is an optimum wedge angle of the wedge target for cutting/grinding from the energy efficiency for grinding, and the optimum wedge angle of cutting tool may be estimated to be 70°-90°.
From the total energy balance of the impact particle and the flat target, the value of the specific fracture-surface energy is also estimated to be 10.1-10.3 kJ/m2 at the optimum impact velocity of 130 m/s where the grinding efficiency is most favorable.
