September 09, 2010

Surface Speeds for Metal Finishing

The effect of surface speed when grinding and finishing metals is addressed in the "Metal Finishing Guidebook", published by Elsevier. They ask us to think of each individual abrasive particle on the abrasive belt as a single point cutting tool. The speed of the belt or number of times a minute each particle contacts the work in a given time frame, will determine the rate of removal and the working life of the individual particle. An increase in the surface speed will cause the pressure to be applied to many more particles in a given time frame and will reduce the penetration of a given particle into the workpiece. When this speed reaches beyond a critical point, rapid dulling of the abrasive grain takes place, the rate of cut decreases, and excess heat is generated.

To resharpen or restore the cutting capacity of the abrasive, added pressure must be exerted to cause fracture of the grain. This added pressure will generate added heat and soon, burning will result in removal of the belt. Conversely, as speeds are slowed, more pressure is exerted on each grain, causing the grain to resharpen with less heat generation. To understand this more fully, the Metal Finishing Guidebook refers us to the following table, where suggested speeds, abrasive, contact wheel, grit size, lubricant and operation have been compiled into a quick reference chart: Suggested Surface Speed and Abrasives for Various Metals.
If you have any questions regarding abrasive belts, please give Abrasive Resource a call at 800-814-7358 or visit us online at www.abrasiveresource.com.

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