普通凝固与快速凝固ZK60合金的耐蚀性能研究

Study on the Corrosion Resistant of Traditional Solidification and Rapid Solidification ZK60 Alloys

采用常规凝固、快速凝固结合往复挤压及正挤压制备了As-cast ZK60和RE-4-EX-RSZK60合金,研究了其组织与耐蚀性能。结果表明,RE-4-EX-RSZK60合金组织细小、均匀,由α-Mg和Mg Zn2相构成,晶内和晶界弥散分布着细小的第二相颗粒。在3%Na Cl溶液中,酸性环境下腐蚀速度最快,碱性最低,而中性介于二者之间。中性环境,Na Cl溶液浓度越高,腐蚀速度越快。极化曲线表明RE-4-EX-RSZK60合金更耐腐蚀,腐蚀电位高而腐蚀电流密度小。

The as-cast ZK60 alloys were prepared with traditional solidification, and the RE-4-EX-RSZK60 alloys were prepared by rapid solidification with reciprocating extrusion and direct extrusion, and the microstructure and corrosion resistant properties were investigated. The results show that the grain size is fine and uniform of RE-4-EX-RSZK60 alloys, it made up of a-Mg and MgZn2 phase, and the fine second phase particles are distribution in the intracrystalline diffusion and grain boundary. The alloys corrosion speed in 3% NaC1 solution is fastest under acid environment, and is lowest in alkali environment, and the neutral environment is between the two. The corrosion speeds are the faster with the concentration of NaC1 solutions higher when the alloys soak in the neutral environment. Polarization curves show that the RE-4-EX-RSZK60 alloys are more corrosion resistant, the corrosion potential is higher and the corrosion current density is small.