コールドスプレー法を用いた高力黄銅膜形成の試み

Abstract

Cu-Zn-based brasses possess excellent strength and corrosion resistance. However, producing bulk brass parts/bodies via conventional powder metallurgy has been difficult due to the high vapor pressure of Zn. This problem is circumvented in Cold Spray, in which solid powder particles, accelerated in a supersonic gas stream, are deposited on a substrate to form dense coatings without long exposure of powder particles to high temperature. In this study, a water-atomized Cu-Zn-Mn-Al-Fe brass powder about 30 μm in average diameter was cold sprayed with and without powder pre-annealing on an aluminum substrate in a nitrogen gas stream heated to 873 K. The as-atomized brass powder consisted predominantly of β solid solution, while the powder pre-annealed at 1023 K had both α and β solutions. Coatings with more than 3 mm in thickness and of nearly full density were produced with or without powder pre-annealing. An increase in deposition efficiency was noted with the coatings sprayed with the pre-annealed powder. Cold Spray provides a viable means for the fabrication of high-strength brass coatings.