Development And Application Of A Fast Quantitative Measurement Meter Of Hydrogen Level In Aluminum Melt

Hydrogen is a harmful element in aluminum alloys. The measurement of hydrogen level in aluminum melt is an important means to check up the degassing effects of aluminum melt, and is very important for improving the quality of aluminum castings.A fast quantitative measurement meter of hydrogen level in aluminum melt with superiority performance and inexpensive price has been developed, which based on the First Bubble Principle and utilized advanced electronic technology, It has the property right of China. Its measurement accuracy reaches 0.01ml/100gAl, and the time of measurement takes only two to four minutes. The measurement error between the meter and the imported fast quantitative measurement meter of hydrogen level in aluminum melt is only 0.0064ml/100gAl, which approves the measurement accuracy of the meter is very well.The effect of melt temperature of ZL102 Al-Si alloy on hydrogen level has been studied. The result shows that hydrogen level in aluminum melt will increase with the rise of the melt temperature, but hydrogen level in aluminum melt in the course of cooling is higher than that in the course of heating in the same temperature.The effect of the holding time of ZL102 Al-Si alloy melt on hydrogen level has been investigated. The result shows that hydrogen level in aluminum melt will increase with the prolong of holding time of the melt, but hydrogen level in aluminum melt will become steady when the holding time is long enough.The degassing effects of the innoxious degassing flux, C2Cl6 and argon gas on ZL102 Al-Si alloy melt have been studied respectively. The results show that the degassing effect of C2Cl6 is better than the others in the same conditions, and the degassing effects of argon gas will increase when the blowing time prolongs in the same conditions, and the degassing effects of argon gas will increase when the staying time prolongs within a certain-time after degassing finished.The change of hydrogen level in ZL102 Al-Si alloy melt before and after modification with sodium-salt modifier (NaF+NaCl) has been studied. The result shows that the hydrogen level in aluminum melt will increase after modification.The relation between hydrogen level in ZL102 Al-Si alloy melt and pinholes rate of casting has been studied. The result shows that the more the hydrogen level in aluminum melt, the more the pinholes in the casting under the same cooling rate. If hydrogen level in aluminum melt is equal, there will be more pinholes in the casting when the casting cools slowly, and the stage of pinholes in standard is higher. The stage of pinholes of casting after modification of aluminum melt with sodium-salt will lower than that of unmodified ones even if hydrogen level in aluminum melt is equal.