The ductility and workability of zirconium allows standard shop equipment to be used for machining and forming operations, with few modifications or new techniques required. There are, however, some special considerations that need to be made when working with zirconium. The information here will provide a starting point for less experienced fabricators, or those working with zirconium for the first time, listing guidelines, recommendations, and specific data when applicable.

MACHINING OPERATIONS

There are three basic principles that should be followed when machining zirconium: slow speeds, high feed rates, and a flood coolant system using a water-soluble oil lubricant. Zirconium does tend to gall and work-harden, which requires higher than normal clearance angles on tools to penetrate the work-hardened surface and cut a clean coarse chip.

In most cases, both carbide and high-speed steel tools give satisfactory results when machining zirconium; however, carbide will usually allow higher productivity and give a better finish. Performance is greatly enhanced by keeping the tools sharp. It is also important to prevent the accumulation of fine chips, since zirconium can be pyrophoric; small machine chips or turnings with a high surface-area-to-mass ratio are easily ignited and burn at extremely high temperatures (see Safety section). Information for specific operations are given below:

Turning

There are no special requirements for turning zirconium. It can be done without difficulty using standard equipment, as long as sharp tools and a coolant lubricant are used. Recommended operating parameters are given in Tables 2 and 3. Lead angles on tools should be between +15 and +60 degrees.

TABLE 2: SINGLE POINT TURNING OF ZIRCONIUM

Two of Ten 1 2 3 4 5 6 7 8 9 10