The Study On Hydrothermal Aging Of Composites And The Corrosion Resistance Of Glass-flakes Coating

Due to its corrosion resistance, the glass fiber reinforced composites is widely used in every field. When it used, the environmental factors of humidity, temperature, light have an important impact on the performance of composites. So the studies of its aging behavior and durability are important. In the first part of this paper, the mass loss rate, matrix structure and the dynamic mechanics performance of composites during the hydrothermal aging were studied, and deduced a calculation formula of the life of composite materials (W%=1%)with the humidity of 95% by fitting the mass loss rate curve at different temperature; In the second part, a dynamic corrosion test enginery was designed, and it was used to study the corrosion resistance of glass flake coating about the SEM, quality, hardness, strength. And the main conclusions were:(1) Mass loss of glass fiber reinforced composites was increased rapidly with the temperature; the calculation result using the formula which is derived by fitting the mass loss rate curve was that composites life at 30℃when w%=1% was more than 7 years with the humidity of 95%;(2) Water absorption of composites increased with increasing temperature, at the first stage, water absorption increased rapidly, then the slope of the curve turned to be smaller gradually,and the curve had a inflection point, and it came to a balance at last and the water absorption was no longer increase over time;(3) After hydrothermal aging, the picture of FIR did not show any new peaks, indicating that there was no chemical reaction occurred during the hydrothermal aging process; DMA test results showed that the glass transition temperature of composites shifted to lower temperature during the hydrothermal aging.(4) Dynamic corrosion testing machine was made and the maximum speed was up to 8000r/min, the radius of sample holder was 95mm. It could simulate the erosion velocity range of 0～15m/s by turning the specimens; (5) Before corrosion tests with the dynamic corrosion testing machine, the samples were smooth and even the flake/resin interface contacted well; after the corrosion test, the sample surface slightly damaged and some glass flakes were exposed; on the broken section of bending samples, some flakes dropped from matrix; because the corrosion made the bond strength between resin and glass flakes became weak;(6) The 854 system which kept the highest flexural strength after corrosion tests about 70.9MPa, the rate of the bending strength change of-6.13%, and the weight increment of 1.28%, showed a good corrosion resistance; The hardness of each system changed with different degreed after corrosion tests, and there is no apparent regularity about the change.