TZM合金热浸铝涂层的显微结构和循环氧化行为

Microstructure and Cyclic Oxidation Behavior of Hot-dip Aluminized Coating on TZM Alloy

TZM合金(Mo-0.5Ti-0.08Zr-0.02C(wt%))是钼基合金中主要的一类高温合金,广泛应用于高温核反应堆、航空、发电和化学工业领域的耐热和结构材料,但是它高温下在空气中却容易氧化。本文采用热浸镀铝工艺在TZM合金表面制备渗镀铝层以提高其高温抗氧化性,热浸温度为730℃,热浸时间分别为3min和5min。研究结果表明:镀层由表面纯铝层和内部合金层组成,合金层主要含有Al4Mo和Al5Mo相;合金层显微硬度达到HV760;镀层与基体间为冶金结合;渗镀铝层的高温抗氧化性能良好。

A titanium-zirconium-molybdenum（TZM）alloy with the nominal composition of Mo-0.5Ti-0.08Zr-0.02C（wt%）is being considered as the prime candidate among various molybdenum-based alloys for applications as heat resistant and structural materials in the areas of high temperature nuclear reactors,aerospace,power generation and chemical industries.However,The TZM alloy has a propensity to undergo rapid oxidation at high temperature in air.Hence the TZM alloy was coated to improve high temperature oxidation resistance by hot-dipping into a molten bath containing Al.The hot dipping temperature was 730℃,and the time was 3,5min respectively.The results show that the coating contains outer pure aluminum layer and inner alloy layer,and the alloy layer is consisted of Al_4Mo phase and Al_5Mo phase whose hardness is HV 760.The aluminide coating is found to be uniform and adherent.It is also found to be adequately resistant to oxidation at elevated temperature.