Experimental studies on gear-honing-tool with laser brazing film CBN
During the process of brazing cubic boron nitride (CBN) gear-honing-tool by Laser, cleaning of the gear-honing-tool and film plating CBN abrasive, and the thickness of brazing coating directly affect the quality and life of gear-honing-tool. In the paper, based on experiment the process of laser brazing CBN is summed up, the thickness interrelationship of brazing filler metal from beginning to end is obtained, the rule of laser facula's moving speed is studied on solder layer thickness and the radial change of gear tooth thickness. It is shown that the bonding among CBN, gear-honing-tool and solder can be realized by laser brazing. In order to improve quality of brazing, the moving speed of laser facula must be reduced along radial direction of gear honing tool. As to different size of CBN abrasive, the thickness of solder layer should be varied so that the bare rates of cutting edge can be ensured. The solder layer thickness should be controlled between 1.25 and 1.5 times of average size of abrasive grains. The thickness of solder layer depends on laser energy and soldering time that can be controlled by the moving speed of laser facula.
Experimental Research of Brazing Monolayer Diamond Grinding Wheel
The paper introduces briefly the technological advantages of a brazed monolayer superabrasive grinding wheel. It must be an inevitable tendency to replace the traditional electroplated grinding wheel in the future due to its excellent grinding ability.The bonding between steel and diamond was performed by induction brazing under controlled temperature and time. The filled intermediate layer materials are reactive metal Cr powder and Ag-Cu alloy foil. The results show Cr carbide film has been formed on the interface between the diamond and the filled intermediate layer, also(FexCry)C between steel surface and the filled intermediate layer. It can be considered that metallurgical bonding has formed in the interface between diamond-intermediate. Finally, contrast grinding experiments with electroplate grinding wheel prove the brazed monolayer diamond grinding wheel has distinct advantages.
The Study of Relationship between Berm Width and Debris Flow at the Slope
The purpose of this study is to estimate the behavior and the mechanism of debris flow at the end of mountain side when a berm was set on the inclined plane. The numerical model was performed by using the Finite Difference Method(FDM) based on the equation for the mass conservation and momentum conservation. In order to measure the behavior of the debris flow, the debris flow of a straight channel slope and the debris flow of channel slope with 3 types of berms were compared. First, the flow discharge and the sediment volume concentration at the downstream of the channel slope, depending on the various berm width and the different inflow discharges at the upstream of the channel were analyzed. The longer the berm width, the flow discharge at the downstream of the channel was decreased and the high flow fluctuation was reduced by a berm. And it means that a berm can effect for the delay of the debris flow. Through Root Mean Square ratio(RMS) comparison, the flow discharge of the channel slope with a berm was lower than that of a straight channel slope. The longer the berm width, for the sediment volume concentration, an inflection point did not show but mild curve. Because the low sediment concentration with water mixture by a berm continuously flow at the downstream end, it will be effect for reducing the disaster caused by debris flow. The results of this study will provide useful information in predicting and preventing disaster caused by the debris flow.