Research Of Interface And Corrosion Behavior Of SiCp/Al Composites

Taking SiCp/Al composite as object of study, this paper made pretreatment of SiC particles(heating and heat preservation for 6h and acid washing at 600℃, high-temperature oxidation for 2h at 1100 ℃, and oxidation for 6h and 10 h respectively) and alloying treatment of basis materials(by adding Mg and Si). Ceramic mould pressureless infiltration technology was adopted to prepare SiCp/Al composite, the corrosion resistance of which was also studied. X-ray diffractometer and scanning electron microscope were employed to make phase and morphology analysis of pretreated particles. Metallographic microscope and scanning electron microscope were also used to observe the microstructure of SiCp/Al. The electrochemical extraction method was taken to observe the interphase morphology, and transmission electron microscope was then used to study the interface characteristics of composite materials. In addition, the corrosion resistance of SiCp/Al composite under different particle pretreatment was evaluated through electrochemical detection and corrosion weight-loss tests. Finally, the corrosion behavior of SiCp/Al composite was studied based on morphological observation and scanning Kelvin probe experiment.The research results indicate that different pretreatment process can change the particle surface morphology and phase composition, with different particles after pretreatment to enhance the preparation of SiCp/Al composite materials with different interface characteristics, high temperature oxidation can hinder the interface reaction, inhibiting the formation of Al4C3, of which after 1100 ℃ high temperature oxide particles preparation of SiCp/Al composites significantly prevented the formation of Al4C3.Through electrochemical extraction found test found that interface is not evenly distributed in the interface, and each interface has a unique morphology;Reinforced, measured by the transmission electron microscopy(sem) interface phase before there is a certain phase relationship.By corrosion test and electrochemical detection, found the above pretreatment scheme different extent improve the corrosion resistance of composite materials, preparation of particles composed by 1100 ℃ high temperature oxidation of SiCp/Al composite materials have higher corrosion potential, the slower rate of anodic dissolution and higher charge transfer resistance and corrosion resistance of the optimal.Mg and Si elements will improve the SiCp/Al composite materials, corrosion resistance, and at the same time, the increase of Mg and Si element content corrosion resistance improved.Study found that by pressureless infiltration pitting corrosion of the preparation of SiCp/Al composites is relatively obvious, to finalize the design point and pitting corrosion pit corrosion pits, attached to the SiC particles, is found through the test of SKP SiCp/Al composite corrosion medium apparent cathode anode area to provide the basis for local corrosion.At the same time, the corrosion process of SiCp/Al composite materials in the early corrosion faster, and the late due to the accumulation of corrosion products, corrosion leveled off.