Multilayers coatings for corrosion resistance enhancement of chromium electrodeposits

chromium multilayers coatings were obtained from three different bath solutions, they were prepared using a square wave current function. two temperatures were studied, 35°c and 55°c varying current density 10 and 70 adm-2. the combinations of different microstructures were studied: columnar and equiaxial. the chromium multilayers were characterized by scanning electron microscopy (sem), x-ray diffraction (xrd), and salt spray (fog) test. in general the coatings are microcracked, have small grain size and show an unexpected very good corrosion resistance, in some cases coatings do not form red rust even after 700 h of salt spray test.