Corrosion of Copper Alloys in Consumer Electronics Environments
C Results of corrosion testing on eight alloys from five copper alloy families common in the consumer electronics industry—copper nickel tin (CuNiSn), copper beryllium (CuBe), copper titanium (CuTi), phosphor bronze (CuSnP), and Corson alloys (CuNiSiX)—are presented. Short-term exposures were conducted in simulated consumer environments such as a salted carbonated cola beverage, artificial human perspiration, and phosphate-buffered saline. Longer-term, conventional salt fog testing, up to 1,000 h, was also conducted. In all of these tests, CuNiSn showed the lowest corrosion rate followed closely by CuBe alloys. Corrosion rates of CuTi alloys were consistently the highest after shortterm testing, while CuSnP showed the highest corrosion rate after salt fog testing.
Corrosion Behaviors of Supersaturated and Peak-Aged CuNiSiCr Alloys under Salt Spray Environment
As promising substitutes for Cu-Be alloys, Cu-Ni-Si series alloys have been investigated intensively concerning their mechanical and electrical properties but without much attention on their corrosion performance. Herein corrosion behaviors and mechanisms of the supersaturated and peak-aged CuNiSiCr alloys are investigated using salt spray test, x-ray diffraction, scanning and transmission electron microscopes. The corrosion rate of the aged sample is lower than that of the supersaturated one due to forming a denser protective corrosion product, Cu2O. Theoretical analyses indicate that the Cu2O film grows by oxidization of the matrix and its granular size is greatly influenced by the precipitates. The second corrosion product Cu2(OH)3Cl/CuCl2·3Cu(OH)2 forms by consuming the oxide Cu2O, which will induce pitting and deteriorate the corrosion resistance. Based on the obtained results, guidance concerning the composition and treatment optimization is provided for enhancing the anti-corrosion capability of the CuNiSiCr alloys.
Heat Transfer Characteristic for a New Plate Metal Hydride Reactor
The property of major metal hydride reactors in the world was analyzed and a new plate metal hydride reactor was designed.An experimental facility to test the metal hydride reactor was also designed correspondingly.The effective thermal conductivity of the plate metal hydride reactor was measured by varying the initial metal hydride packing fraction,the kind of filled gas and the pressure of the filled gas,cycle numbers.The test results show that the effective thermal conductivity of the reactor,has exceeded(7.5) W/(m·K) before activation,which is increased greatly.After alloy activation,the effective thermal conductivity of the reactor has a linear change trend with the hydrogen pressure during the interval 0.1~3.5 MPa.The effective thermal conductivity of the reactor just only decreases quickly at the beginning,but becomes stable after several cycles.