腐蚀对sic/Al(L2)和sic/Al-Ni复合丝力学性能的影响~①

THE EFFECT OF THE CORROSION TO THE MECHANICAL PROPERTIES OF SIC/PURE AL AND SIC/AL-NI PRECURSOR WIRES

本文对SiC/Al(L2)和SiC/A1-Ni复合丝在蒸馏水和在3.5％NaCl溶液中的耐腐蚀性能进行了研究。通过测试腐蚀前后复合丝的抗拉强度,利用气相色谱、发射光谱、X射线衍射等手段分析腐蚀气体和腐蚀产物,观察金相和扫描电镜下形貌的变化,发现SiC/A1复合丝在室温蒸馏水中36天、50℃和75℃蒸馏水中各15天浸泡后,其抗拉强度基本保持不变,说明该类复合材料对潮湿环境具有良好的耐腐蚀性能;SiC/A1-Ni复合丝在3.5％NaC1溶液中浸泡后,其抗拉强度随溶液温度升高和时闻延长而逐渐下降;其腐蚀主要是选择性腐蚀,其次是孔蚀和缝隙蚀。

In this paper, the corrosion resistant propeties after immersed in the distilled water and in the 3. 5%NaCl solution for SiC/pure Al and SiC/Al-Ni precursor wires have been studied. The tensile strength of the precursor wires of the noncorrosion and the corroded was measured. The corrosion gases and the corrosion result were analyzed by the means of the gaseous phase chromatogram and the emissivity spectrum and the X-ray diffraction, The morphologyof the composite plate of the noncorrosion and of the corroded were observed with the metal-loscopy and the scanning electron microscope. The result is shown: the tensile strength is maitained until 36 days at room temperature, and until 15 days at 50℃ and 75℃ in the disstilled water for SiC/Al precursor wire. The rate retained stregth are 97. 4%,97. 2% and 95.1% re-spectivily. This composite shows very good corrosion resistant property. For SiC/Al-Ni precursor wire, the time immersed in the 3. 5% NaCl solution is long and the solution temperature is incremental , the tensile strength is reductive. The corrosion mechanism of the SiC/Al-Ni precursor wire is first selective corrosion,secondary is the void corrosion and the crevice corrosion.