Papers by Author: Wen Feng Ding

Abstract: Monolayer brazed diamond tools, which are high bonding strength at the interface between brazing alloy and grits, are becoming the active field in which improvements in processing and advanced products can be anticipated. Some researchers proposed brazing diamond methods with Ni-Cr and Ag-Cu-Ti alloy, but there is a shortage of the comparative study of the characteristics of the brazed diamond tools fabricated with the different brazing alloy. In this paper, machining performance experiments have been carried out, including contrast tests about tool life and machining efficiency for thin-walled monolayer brazed diamond core drills fabricated with Ni-Cr and Ag-Cu-Ti alloy. The results show that the Ag-Cu-Ti alloy can improve the machining performance. Wear mechanism of diamond grits was studied in those drilling processes. The results show that the low ratio of grit breakdown of the core drill using Ag-Cu-Ti alloy is the key factor of its longer life. Furthermore, based on the experimental results, the areas of the grits wear flat increase the feed force, and decrease the machining efficiency.

Abstract: Multilayer brazed CBN wheel segments based on graphite self-lubricating has been fabricated. The bending strength of wheel segments was measured and the fracture morphology of tested segments was detected. The results show that the bending strength of segments with CBN grains decrease to a small extent from 116MPa to 97MPa with the linear increase of graphite content from 5 wt.% to 15 wt.%. Due to the poor strength and certain stress concentration by the added graphite, the fracture interface transfers from the whole CBN grains to the bonding matrix with the increasing of the graphite. In addition, the pore sizes are decreased obviously.