Papers by Keyword: Fluxing

Abstract: In this paper the effect of Ca on the formation of Si phases during solidification of commercial purity Al-15Si alloy was studied. The Ca impurity level of the commercial purity alloy was 200 ppm which was sufficient to lead to a modified Al-Si eutectic. After the addition of K₂SiF₆ flux the Ca impurity level was 20 ppm which was insufficient to modify the eutectic Si, but primary Si was refined from 48 µm to 20 µm. The refinement of primary Si in Al-15Si alloy fluxed with K₂SiF₆, suggests that when Ca level is reduced to less than 20 ppm the impurity level of P (≈20 ppm) in commercial purity hypereutectic Al-Si alloys is sufficient to refine the primary Si without any deliberate addition of P. In the case of adding 0.5 wt.% Ca to the Al-15Si alloy, the eutectic Si was highly modified and the primary Si was coarse and irregular in morphology (unrefined). The addition of such a high level of Ca led to enhanced quantities of entrained oxide inclusions/bifilms. The first phase to solidify was Al₂CaSi­₂ which nucleated on the oxide bifilms. Primary Si then formed by nucleation and growth on the Al_2­CaSi₂ particles.

Abstract: Through the orthogonal experiment, research on the process parameters of the qualiity coating with the new auxiliary ,such as different pickled time, parched time, hot-dip time , and analyzed by scanning electron microscopy, X-ray diffraction. The results show that BiOCl is a new fluxing agent and the optimal parameters for pickled time, the parch time , hot-dip time, respectively,10s,120s,9s,through this we can get bright, smooth, corrosion resistant coatings

Abstract: Through the orthogonal experiment, research on the process parameters of the qualiity coating with the new auxiliary ,such as different pickled time, parched time, hot-dip time , and analyzed by scanning electron microscopy, X-ray diffraction. The results show that BiOCl is a new fluxing agent and the optimal parameters for pickled time, the parch time , hot-dip time, respectively,10s,120s,9s,through this we can get bright, smooth, corrosion resistant coatings.

Abstract: The costs of salt flux treatment have received a strong industry focus as solid flux addition has replaced the usage of Chlorine for alkali and inclusion reduction. The magnesium chloride component has historically had the higher cost incidence but since 2008 the potassium chloride component because of its role as feedstock of fertilizer production has been subject to large commodity price driven fluctuations and rose 350% in 200 – 2009. As demand for world food production and bio fuels increases as the global economy recovers further price rises can be anticipated. A programme of work and field results are presented on the development of an alternative flux system based on a ternary composition.

Abstract: A comprehensive introduction of current aluminum refining technology is reviewed in this work especially the effects of chlorine on refining process is discussed. The mechanism of chlorine on improving hydrogen diffusion has been studied by ab initio molecular dynamics calculations and we obtain the diffusivity of hydrogen in liquid aluminum which is in agreement with the experimental data. It can be concluded that the diffusion of hydrogen in aluminum melts can be enhanced on the presence of chlorine.

Abstract: A spectral absorption of the ferrous ion in fluxing was investigated in this paper due to the significant effect of ferrous ion on the quality of hot-dip galvanizing production. Based on analysis of spectrophotometry, an automatic detection equipment of ferrous ions is developed according to its special characteristics. On-line measuring of ferrous ion in fluxing of the hot-dip galvanizing is realized by the micro-pump and the equipment. Results show that the lowest limit to be detected is 0.1 g/L, measuring errors are less than 0.05 g/L, the linear equations of the absorption and concentration of the ferrous ions shows a good correlation coefficient which is 0.99995 when the ferrous ions concentration is between 0.1g/L and 10g/L in fluxing.