Yoshiaki Hagiuda

Examination of Plating on ABS Plastics and Its Adhesion under Electron Microscope

This paper reports the research on adhesion mechanism of electroless plating on ABS plastics under an electron microscope. Peeling test was conducted to determine the adhesive strength between copper and the plastics. It was indicated in normal plating conditions that peeling did not occur on the interface between plastics and metal, but on the surface layer of the plastics; and the adhesive strength depended upon the strength of the surface layer of the plastics. Hence, the molding and etching conditions of plastics had powerful effects on the adhesive strength. The above effects would be caused by the presence of internal stress and orientation in the contact part with the mold which made that layer concentrically brittle. The presence of such layer was observed under the electron microscope. The etching conditions had effects on the formation of dovetail joints. Stronger adhesion was produced by the formation of numerous joints under proper etching conditions. However, the parts of anchoring were limited on the whole, and chemical combination would also be taken into consideration for adhesion mechanism.

The Specular Gloss and Crystal Structure of Electro-deposited Chromium. (Part 2)

Electron micro-structure of the electro-deposited chromium is discussed. The structure of the bright deposits gives very fine crystals of the order of 10-6cm, whereas Hume-Rotherys results by X-ray diffraction method gave the order of 10-7cm. The crystal size of milky or matted surface is larger.The crystal structure of chromium deposited from the bath c is hexagonal compact or bodycentred cubic, but their structure changes to a (110) orientation (b. c. c.) after half an hours electro-deposition.