三元层状氮化物Ti_4AlN_3的抗腐蚀性能

Study on the Corrosion Resistance of Layered-Ternary Nitride Ti_4AlN_3

研究了以热压烧结合成的Ti_4AlN_3块体材料在浓和稀HCl,HNO_3以及NaOH中浸泡100 d的腐蚀行为。结果表明,Ti_4AlN_3在HCl中主要表现为孔蚀和晶间腐蚀,且在浓HCl中的失重要大于稀HCl;由失重曲线可见Ti_4AlN_2在浓HNO_3中失重最大,为11.73 mg/cm^2,由腐蚀面SEM照片可见较严重的全面腐蚀和剥蚀,XRD图谱显示一部分Ti_4AlN_3由于失去Al层从而转变为在酸碱中更为稳定的TiN。在酸溶液中,Ti_4AlN_3晶体的Ti-Al,Ti-Ti和Al-Al键发生断裂,Ti,Al原子溶解在溶液中。Ti_4AlN_3在NaOH中几乎没有失重,表现出良好的耐碱性能。

The corrosion behaviors of bulk Ti4AlN3 which was synthesized by the hot-pressing method were studied by immersing samples in concentrated and dilute HCl, HNO3, and NaOH solutions for 100 d. In both concentrated and dilute HCI solutions, pitting and intergranular corrosion was occurred. Besides, the sample immersed in the former solution has more weight loss. Weight loss curves indicate that Ti4AlN3 immersed in concentrated HNO3 has the max weight loss of 11.73 mg/cm^2. The eroded and flaked surface of the samples can be observed clearly by SEM. XRD patterns show that a part of Ti4AlN3 changes to TiN due to the loss of Al layers in acids. Ti and Al atoms dissolved in the acid solutions because of the fracture of Ti - Al, Ti - Ti and Al - Al bonds. In NaOH solutions, Ti4AlN3 is very stable without distinct weight loss.