Grinding

Facts about Grinding

 Grinding is a process of material removal in which a wheel composed of many hard abrasive grits wears away a softer material.

Almost any material can be ground - aluminum, steel, ceramics, even diamond or glass.

Grinding is used to form countless types of products such as automobile engines, sharp edges on knives, ball bearings and drills. The smooth, accurate surface of the Hubble Telescope lens was formed by a process of grinding and polishing.

The sparks are a result of small fragments of metal - grinding chips - being rapidly sheared from the surface at high temperatures and burning in the atmosphere.

The State-of-the-Art in Grinding: The grinding process is under continuous improvement. Research at universities and in industry means that the science of grinding is constantly advancing - resulting in increased production, saved revenues and higher quality products for the consumer. One of the most recent breakthroughs has come from special micro-fracturing abrasive grits grown from seeds and from high-speed grinding at wheel velocities of 700 miles per hour (1100 km per hour) using synthesized man-made abrasives such as Cubic Boron Nitride in special bonding materials.

Many engineers believe that we are on the verge of a revolution in manufacturing with grinding leading the way.

Books on Grinding

There are numerous books on grinding. I find the following to be very useful.

1. Principles of Abrasive Processes, M Shaw. In-depth, theoretical and very interesting.

2. Precision Grinding, V Repp. The grinder's bible - theoretical yet practical.

3. Creep-Feed Grinding, Andrew, Howes & Pearce. Thorough coverage of large depth-of-cut grinding.

4. History of Tribology, D. Dowson. A history of abrasion from Neanderthal Man to present. Fascinating reading.

The Future of Grinding

Until recently, grinding was a poorly understood process. The grinding engineer had to rely on improvements via the slow and tedious method of trial and error. Grinding is still something of a black art and, although a large mystique still surrounds the grinding process, a better understanding of the mechanics behind it has meant greater progress based on a more scientific approach.

This increased understanding along with recent technological developments means that grinding is being used more-and-more in industrial processes. Separate milling and finish grinding operations can now be replaced by a single creep-feed grinding operation, saving time and money. These new developments mean that high production rates can be accomplished without damage to the workpiece caused by excessive temperatures.

A recent cover story on creep-feed grinding in Cutting Tool Engineering predicts massive growth for the industry in the coming years.

How Grinding  Is Used 

Grinding is used whenever something needs to be smoothed or shaped. Nearly anything can be ground—steel, ceramics, glass, or even diamonds. It's used on auto engines, to make knives sharp, and to create drills and ball bearings. Telescope lenses to peer into outer space are made by grinding.

        Advances In Grinding

        Despite its Neolithic origins, grinding is still being studied and improved upon. Industries and universities research how to improve the grinding process to save money and create better products. One new application is using seeds to grow micro-fracturing abrasive grits. Another is creating wheels that go at 700 MPH.

Types of Grinding

 
In the past, grinding wasn't really studied as a process. People improved on conventional grinding by using trial and error, which was tedious and didn't lead to many new advances. Today, mechanical engineers study the process of grinding. There is even an Abrasive Engineering Society!