Shaping and Machining Tungsten - Tips and Ideas for You
Many tungsten dealers in the US and other countries are striving to find a way to reduce metal wastage during tungsten machining.
February 8, 2014 (Newswire.com) - Tungsten/Wolfram (W) is a hard and abrasive metal, so it is tough to machine without creating chips. It's tougher to cut and shape than titanium and stainless steel. Some tungsten alloys are also highly elastic and stiffer. They demand enough spindle torque and stronger cutting tools than either unalloyed tungsten or alloys that contain a low amount of tungsten. Another common problem for low-percentage wolfram alloys is that they are very ductile to the point that they create constant chips when being machined. Hence many tungsten dealers in the US and other countries are striving to find a way to reduce metal wastage during tungsten machining. This metal requires adequate time to cut because at very high speed it produces a lot of heat that damages the cutting equipment.
1. What makes successful machining?
First the machinist should reduce or control vibration. This can be achieved based on how they hold the tungsten part they are cutting. Since tungsten metals are tough and dense, the part being cut should be held firmly until it is successfully machined. If they are allowed to vibrate, the tools used will cut as well. The second technique for vibration control has to do with tool choice. The best tools should resist vibration and be very stiff as well. It should have a sharp cutting edge and suitable carbide coating and grade. Each tungsten alloy must be cut uniquely, explaining why having precise cutting parameters beforehand is important. Those who want to succeed in tungsten machining must have the best quality coolant. So far, every other tungsten supplier uses sulfur oil. It is mixed with water where oil makes about 20% of the blend to reduce cooling costs and boosts the life of the tool.
Wolfram can be made into several shapes and structures. Manufacturers can stamp, bend, fold, spin, rivet and trim it as they desire. The problem with tough and strong tungsten is that it can break at room temperature. Hence, it requires not only proper tools but also skill and careful handling. When shaping tungsten a machinist must remember the following rules. First, they must ensure that the room temperature is above tungsten's transition temperature. This transition temperature must be regulated all through the machining process. Care should be taken when using a coolant to chill the cutting tool. One must ensure that the tool does not rapidly chill the part being shaped to avoid damaging it. Commercially viable machined tungsten should never be heated above its known re-crystallization temperature level. It will simply break and be of no use to the tungsten producer. When bending wolfram to the rolling direction of the part, a perpendicular position should be maintained. Also bending radius should be big. The very last step in shaping tungsten parts is done with a grinding machine. The best machine usually has silicon carbide grinding wheels and a grain size of one hundred to one hundred and twenty. When tungsten is being soldered to other metals or itself, a lot of caution is observed. This is usually done with tungsten rivets. Also tantalum rivets are good alternatives.
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Stanford Advanced Materials (SAM) Corporation is a global supplier of a series of pure metals, alloys, ceramics and minerals such as oxides, chlorides, sulfides, oxysalts, etc. Our headquarter, located in Irvine, California, USA, was first established in 1994, starting to provide high-quality rare-earth products for research and development (R&D).