Bismuth Alloy (Woods Metal)
Woods metal is a homogenous mixture (Eutectic Composition) of Bismuth, Lead, Tin and Cadmium.
This produces an alloy with a single melting temperature that is lower than the melting point of any of the constituent metals. The Eutectic melting temperature is approximately 70°C.
This very low melting point makes Woods metal useful in many applications. For example, Woods metal is very useful when bending thin-walled metal tubes. In this application, the woods metal can be melted and poured into the tube. It can then be allowed to solidify. With the Wood’s metal in a solid state the tube can then be bent to shape without collapsing the tube in the process. Once the work has been done, the Wood’s metal can then be removed by immersion in boiling water.
It is important to note that Wood’s metal contains Cadmium and therefore must be handled with great care. You can view details of the possible health hazards of different forms of cadmium and the preventative measures your employer needs to apply and the precautions you should take here.