Metals in Lighting Fittings

The choice of commercially available metals and alloys which have the necessary characteristics for lighting fittings is extremely broad but in practice the range of alloys actually used is small. The primary characteristics include adequate mechanical strength and ductility; a relatively high strength-to-weight ratio; corrosion resistance in a wide variety of environments; the ability to be formed or cast into complex shapes; and the ability to acquire a surface finish which is either technically or aesthetically desirable. The reasons for the restriction on the range of alloys which are used are discussed and the limitations of the available materials are considered.Trends in the development of new metallic materials which are likely to be of interest to the lighting engineer are described. The significance of current investigations on new processes for both the primary and secondary fabrication of metals are also considered in relation not only to the production of complex forms but also to their possible effects upon the overall cost of finished parts.