高硅铝合金新型酸洗除灰技术研究

New Pickling and Ash Removal Technology of High-Silicon Aluminum Alloy

为开发一种安全环保的高硅铝合金酸洗除灰工艺,以ADC12压铸铝合金为研究对象,以试样表面洁净度、表面均匀性、溶液稳定性为主要技术指标,系统考察了不同添加剂对H2O2-NH4F复配体系除灰效果的影响规律,探讨了相关机理。获得最佳除灰液配方如下:过氧化氢80 g/L,氟化铵200 g/L,磷酸100 m L/L,一水合柠檬酸60 g/L,稳定剂5 g/L,常温,时间45 s。最佳除灰溶液对传统碱洗工艺产生的硅灰表现出优异的清除效果,表面Si含量仅1.37%;除灰液稳定可靠,使用后放置30 d,H2O2分解率仅1.27%。

In this paper,a safe and environmental pickling and ash removal technology for high-silicon aluminum alloy was developed. The effects of different additives on the pickling and ash removal efficiency of H2O2-NH4 F composite system were systematically investigated based on technical indexes such as the sample surface cleanliness,uniformity and solution stability for ADC12 die-casting aluminum alloy,and the relevant mechanisms were explored as well. Results showed that the obtained optimum ash removal technology conditions were as follows: hydrogen peroxide of 80 g/L,ammonium fluoride of 200 g/L,phosphoric acid of 100 m L/L,citric acid of 60 g/L and stabilizer of 5 g/L,room temperature,time of 45 s. The optimum ash removal solution had excellent removal effect on silica fume produced by traditional alkali washing process,and the surface Si content was only 1.37%. The solution was stable and reliable with the decomposition rate of H2O2 of only 1.27% for 30 d.