چكيده به لاتين
Shotpeening is a complex and random process that is controlled by some process input parameters. The results of this process are increasing the surface roughness, distributing the residual stress at depth and surface, compacting the grain boundaries at the surface and increasing the strain hardening of the target material. In the present study, the parameters are first divided into two general categories, and then using single-shot simulation, the effect of process control parameters on surface roughness and tribological behavior is investigated and after determining the appropriate constitutive model of the target material based on matching depth residual stress distribution And the surface of the sample in the actual state of the process and simulation, a method is proposed to achieve complete coverage by multiple collisions in a reference area. The results show that the surface roughness is strongly affected by the velocity and diameter of the impact ball and with increasing process time, the roughness parameters will behave differently from each other. Ra parameter decreases due to overlap and then increases with increasing process time and will be reached to a stable value. Rapid growth and then gradual decrease of parameters Rz, Rt are related to the equivalent plastic strain and process time and the rate of deformation at the surface, with the production of cavities at the reference level, these two parameters will grow upwards. With the continuation of the process and subsequent collisions, the rate of this increase decreases and finally, with the complete coverage of the surface gradually and the overlap of the production cavities, they take a downward behavior. The Rt factor will not give specific information about the uniform distribution of roughness on the surface. On the other hand, surfaces with different states can have similar values of Ra. The Rz factor is very sensitive to changes in the height of the surface profile so it can be an accurate parameter in examining the uniformity of the roughness distribution. Simultaneous consideration of the two parameters Rt, Rz provides more accurate information on the uniformity of roughness induced by the surface due to the shot. As the percentage of coverage increases, both factors tend to be almost constant, indicating that there is a uniform distribution of roughness in the reference area, which is consistent with the experiments performed.
