The Influence Factors Of ZL702Alloy Hydrogen Solubility In Research

With the need for the development of industrial technology， The performancerequirement of aluminium and aluminium alloy castings is becoming more and more high.Thestudy found that：Porosity caused by the rejection rate of all scrap aluminum castings for morethan40%.To improve the quality of the casting， which is one of the key technologies toprovide high-quality aluminum alloy liquid in the actual production，and an important factorin improving the quality of liquid aluminum is aluminum liquid hydrogen content.So that，themechanism of hydrogen absorption liquid aluminum，the study of factors affecting thesolubility of the other aspects of a very important significance.This article is based on decompression solidification principle, mainly studied thefollowing contents：①From the perspective of thermodynamics and kinetics and mechanismof aluminum liquid hydrogen absorption stage of dehydrogenation to analyze，and find thefactors influencing the aluminum melt except for hydrogen purification process，summarizesthe basic way to improve purification process；②Determine the severity of pinhole ofaluminum castings has carried on the oretical derivation，the relationship formula is obtainedobtained，to reduce the casting pinholes,we can take the following measures: reducing thehydrogen concentration in the alloy begins to crystallize time，try to avoid liquid aluminumreact with hydrogen substances or contact and strengthen the purification process of moltenaluminum； Improve the aluminum liquid crystalline when outside pressure such as takingpressurized solidification.Studying the effects of alloying elements on the hydrogen content of the alloy ZL702，we draw the following conclusions:①Si and Cu alloy elements will tend to reduce thehydrogen-absorbing aluminum melt；②Mg will increase of aluminum melt hydrogenabsorption tendency. And with the increase of Mg content in liquid aluminum，aluminum melt have more and more fracture in surface oxide film，and the crack width is wide，the chance ofthe internal fresh liquid aluminum contact with the water vapour in the atmosphere haveincreased，the speed of aluminium liquid hydrogen have increased too；③And Mn had littleeffect in the solubility of hydrogen in aluminum liquid.Bystudying process parameters affect ZL702alloy hydrogen content,conclusions are asfollows：①ambient humidity is a key factor ZL702aluminum melt hydrogen content ofinfluence.When the alloy casting temperature is constant，the higher the relative humidity，thehigher the hydrogen content of the melt；When using C2Cl6refining ZL702alloy，after refiningof liquid aluminum with the extension of incubation time first decreases increased hydrogencontent,after refining standing15min，the minimum amount of aluminum liquid hydrogenwas0.04ml/100gAl；In the same ambient temperature and constant ambient humidity，thehigher the holding temperature of liquid aluminum， the greater the solubility ofhydrogen.When the heat preservation temperature from710℃to790℃，the hydrogendissolved from0.06ml/100gAl rise to0.15ml/100gAl；④Through experimental test measureZL702alloy hydrogencontent prediction formula： thehydrogen partial pressure in a real experiment put into the formula，we can find that thesolubility of hydrogen in molten aluminum is0.273ml/100gAl，with the experimentalmeasuring hydrogen in the hydrogen content is basically the same and the error was2.8%.