Why is titanium considered a ferrous metal

Machining of titanium

Home 3/11/2019 Titanium is a shiny silver metal that occurs underground in the form of titanium ore. In addition to steel and aluminum, it is one of the most common metals. Titanium can only be used in the form of alloys as a material for various technical applications that differ from one another in terms of processing, strength and weight. The main characteristics of titanium and the various titanium alloys are, on the one hand, a low component weight, high strength, high thermal load capacity, good corrosion resistance and, what makes it ideal for use in the medical field, good bio-compatibility.

Mechanical machining

The disadvantage of titanium is a relatively complex mechanical processing. All titanium materials tend to stick and smear the tools if they are too hot during the machining process. This can only be remedied through reduced cutting speeds and increased feed, as well as through very intensive cooling.

Machining

The machining of titanium takes place under similar conditions as the machining of ferrous metals and steels. However, due to the high strength of the material, other machining parameters are required when CAD-controlled machine tools and hard metal cutters are used. The high strength of titanium leads to extremely high stress on the tools through wear and heating, which is why the cutting speeds can only be about a third as high as when machining steel. Intensive cooling and lubrication is necessary in order to absorb the high forces during machining; all devices and machines must have a high degree of internal rigidity. In order to achieve the thickest possible chip and to reduce friction, the highest possible cutting depths are set so that different alloys can basically be machined similarly depending on their composition.

Turning titanium and its alloys

Tungsten carbide plates are the ideal tool for turning titanium, and the turning tools used should be made of cobalt or diamond. The classic high-speed steel can in principle also be used for turning titanium, but increased wear of the tools must be accepted; the cutting parameters such as feed rate and cutting force must also be adjusted on the lathe. If, in exceptional cases, a large feed has to be used, this can only be achieved with specially tempered turning tools. Polished surfaces must be constantly checked by measurements, but can only be achieved on the lathe with an uninterrupted cut.

Milling titanium

Machining titanium by milling is extremely difficult. On the one hand, the chips tend to stick to the milling tool, and on the other hand, the formation of hardened cutting edges known from steel processing must be seen and prevented in this context. When milling, small cutting angles and sharp cutting tools made of hard metal must be used; In addition, the depth of cut must generally be high enough to produce chips that are sufficiently thick, because this can prevent smearing or the formation of cutting edges.
It is also advantageous to be able to machine titanium by down-milling in such a way that the usual load on the milling tool is reduced. The reward for the effort in processing, however, are visually appealing products of high precision, low weight, high strength and low tendency to oxidize.
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