Influence of brazing filler thickness on joint stress of two different pick operation processes

In order to investigate the cemented carbide head shedding phenomenon of picks,the stress distribution of brazed joints in pick working process and the influence of brazing filler thickness on the brazed joint stress were stud-ied. Using the ANSYS software,the elastic-plastic thermodynamic models of common pick and wear-resistant pick were established respectively. The thermal-structural sequential coupling analysis of the two picks were carried out to obtain the distribution of brazing residual stress,and the correctness of the models were verified by experiments. The working temperature and load of the pick were applied to the brazing residual stress model,and the stress distribution of the brazed joint was simulated. The results showed that ① under normal conditions,the maximum residual brazing stresses appeared at the interface between brazing filler and cemented carbide head of the two picks,which are prone to the cracking of the brazing seam caused by excessive thermal stress. ② Under working condition,the maximum stresses of brazed joints of common pick and wear-resistant pick were nearly equal in the radial path,reaching about 210 MPa, but the locations of the maximum stress were different. The maximum stress of common pick was located at the inter-face between brazing filler and pick body,while the maximum stress of wear-resistant pick was located at the interface between brazing filler and cemented carbide head. On the axial path,the maximum stresses of the two picks were not much different,and both of them appeared on the outer surface of brazed joint. Wear resistant layer has little effect on the overall stress distribution of pick,but it made the position of the maximum stress of pick shift and changes the dan-gerous position of cemented carbide head shedding. ③ Both common pick and wear-resistant pick have the minimum joint stress when the brazing filler thickness is 0. 1 mm,which makes the connection performance of brazed joints the best.