Diamond-coated tools are intended for use in machining of carbon fiber reinforced plastics and dry processing of metals such as aluminum alloys and stainless steel. To guarantee the reliability of the coated tool, quantitative evaluation of the adhesion strength of the film onto the substrate is necessary. This study examines the development of an indentation tester for the evaluation of diamond film adhesion properties. The indenter point shape resembles that of the Rockwell C scale. This tester detects acoustic emissions continuously during the indentation of the diamond indenter against the film. This method defines the critical load to yield a crack on the film as the adhesion property of the film. Results show that the tester works satisfactorily for the quantitative evaluation of peeling or cracking strength of the film. The effect of the diamond material on the indenter lifetime is also discussed according to the longest lifetime for the binderless polycrystalline diamond.
To improve the wear resistance of Cu/Ni multilayer films, a Cu-Sn-Ni alloy boundary layer was formed between Cu/Ni layers through repeated electrochemical deposition of Cu, Sn, and Ni, and by annealing of the Cu/Sn/Ni/Sn multilayer film. The wear resistance of the annealed Cu/Sn/Ni/Sn film was higher than that of the Cu/Ni film, but the wear resistance of a single layer of Sn is much lower than those of Cu and Ni. The XRD and XPS measurements of the annealed Cu/Sn/Ni/Sn film indicated that the Cu-Sn-Ni alloy was Cu2Sn3Ni3 alloy, with Sn atoms distributed at the interface of Cu/Ni layers. Results suggest that an increase in adhesion of Cu and Ni layers with the boundary layers improved the wear resistance of multilayer films.
Currently, the main method used to maintain adhesion between Cu and insulating material （resin） on PWB is forming roughness on a Cu surface using chemical etching and acquisition of adhesion by the anchor effect. We conducted an examination with the intention of using the technology to maintain sufficient adhesion with the etching solution that forms fine roughness by approximately 1/10 of the etching amount of a conventional micrometer-order etching solution.
Effects of alloying elements in aluminum alloys on adhesion of electroless nickel-phosphorus plated films were studied for Al-Mg, Al-Zn, and Al-Zn-Mg alloys. Although the plated films on Al-Zn alloy exhibited high adhesion, those on Al-Mg and Al-Zn-Mg alloys peeled easily. However, adhesion on Al-Zn-Mg alloy was improved by reducing the magnesium concentration to 0.2 at%.
The carbon conductor is exfoliated from the aluminum current collector when overcharged. That exfoliation results from stress caused by volume expansion of the carbon conductor, not from electrolyte wetting, internal electrostatic force, or a carbon intercalation reaction. Electrolysis of the anion is the reason. Therefore, we are taking care to evaluate adhesion properties not only at coating, but also at charging.