Analysis of surface blistering in the manufacturing of faucets

Abstract

This research aimed to carry out an analysis of the surface blistering problem in the manufacture of faucets. Zamak 3 is a material produced by high-pressure die-casting. The surface blistering microstructure was examined with an optical microscope and a scanning electron microscope, while gas properties were examined by using gas chromatography. The results from optical and scanning electron microscopy showed discontinuities in the zinc layer, including a large amount of porosity spreading all over the product on the surface of the zinc layer as well as blistering under the surface. The gas chromatography showed that the average amount of hydrogen gas was 0.00755 percent, supporting the hypothesis that the discontinuities are caused by the porosity containing gas inside the base metal, and the heat during liquid metal injection is the main factor driving gas expansion, affecting the discontinuities.