Selected Metals - 10: Other Metals
|WARNING: Machine tools present a safety hazard. Improper operation can result in severe injury. These topics are for non-laboratory study only and are not to be used in conjunction with the operation of any tool or machine described herein. Never use a machine tool without the supervision of a qualified instructor.|
A list of metals and alloys not covered in this topic would be very long. But the four mentioned below are - in this authors opinion - the most common "other metals" found in the machine shop.
The term cast iron, like the term steel, identifies a large family of ferrous alloys. Cast iron has higher carbon and silicon contents than steel. Because of the higher carbon content, the structure of cast iron, as opposed to that of steel, exhibits a rich carbon phase. Two basic types of cast iron can be identified visually: White Iron and Gray Iron. The machinability of cast iron is relatively good. However it must be machined without coolant so particular attention to heat build up is essential. Cast iron machining produces a powder instead of a chip.
Titanium has developed a mystique as a nightmare to machine. This is simply not the case. Experienced operators have compared its characteristics to those found in 316 stainless steel. Recommended practice includes high coolant flow (to offset the materials low thermal conductivity), slow speeds and relatively high feed rates. Tooling should be tungsten carbide or cobalt type high speed tools.
Conventional machining techniques used for iron based alloys may be used. Machining characteristics are somewhat similar to those for the austenitic (300 Series) stainless steels. This alloy does work-harden during machining and has higher strength and "gumminess" not typical of steels
Conventional machining techniques used for iron based alloys may be used. This alloy does work-harden during machining and has higher strength and "gumminess" not typical of most steels. Heavy duty machining equipment and tooling should be used to minimize chatter or work-hardening of the alloy ahead of the cutting
label: stainless steel, aisa, sae, aluminum, copper, tool steel, history of metal