Applications and Industries Served
Work Holding / Encapsulation
Alloys are used to hold special or irregular shaped pieces in polishing and machining operations. As an example, Cerrobend and Cerrotru secure thin foil sections on jet-engine turbine blades, allowing them to be machined more accurately.
Cerrobend and Cerrobase are used to support thin-walled tubing and channels during bending or forming to prevent wrinkling, flattening, or rupturing of the part. The growth property of the alloys ensures complete filling of the part. Cerrobend is used for this application, as it can be melted out with hot water. Cerrobase is used for tubes with diameters larger than 1½”.
Safety and Fire Protection
One of the earliest uses of fusible alloys was as the melt-out element in sprinkler heads. Various alloys are used depending upon the temperature requirement for the application.
The alloy is used to attach optical lens blanks to surfacing blocks for polishing and grinding. For plastic Cerrolow 117 is recommend. For glass several alloys can be used: Cerrobend, Cerrolow 136 (cadmium free), and Fields Metal (cadmium and lead free).
Radiation Therapy Shielding / Blocking
Thermal Release Mechanism
Various temperatures are used to produce fusible links for fire doors, range hoods, safety plugs in pressure relief values and compressed gas tanks as well as thermal vented fuel caps.
Mold / Cores
Molds are expensive and time consuming to make, so fusible alloys are used. Fusible alloy mold are permanent and can be used an almost unlimited number of times. The low temperature makes fusible alloys useful for electroforming external and internal shapes of copper, iron or nickel parts. A core is made from the fusible alloy, copper or nickel is then deposited on surfaces; finally the core is melted out, leaving a dimensionally precise part with a smooth surface finish.
Proof Casting - Chamber Casting
Small cavities are proof cast with solid casting of low melting point alloys. Cerrolow 117 is often used for this purpose due to its low melting temperature. Cerrosafe 160/190 is used in the proof casting of gun chambers due to its initial shrinkage and then growth to zero shrinkage or growth after one hour.
Bismuth is one of the few elements that expands on solidification from liquid to solid phase and it is one of the reasons why a bismuth based fusible alloy was selected as the sealing medium for down hole sealing in the oil and gas industry. Bismuth based alloys are corrosive resistant and non-toxic.