Outgassing Properties of Various Surface Finished Aluminum Alloy Measured by Extremely High Vacuum System

摘要

The outgassing rates of aluminum alloys (A5052) with four types surface finishes, i.e. conventional mechanical grinding (MG), mechanical grinding with optimized process (OMG), combination of mechanical grinding and chemical polishing (MG＋CP) and combination of optimized mechanical grinding and chemical polishing (OMG＋CP), were investigated using the measurement systems with ultimate pressure of 10~(-10) Pa. For without baking, the outgassing rates of all surface finished aluminum alloys were changed in time from 10~(-7) to 10~(-8) Pa m~3 s~(-1) m~(-2) from 5 to 70 h after the start of vacuum pumping and MG>>OMG ≈ MG+CP ≥ OMG＋CP was obtained for these rates. For after baking, the outgassing rates of all samples showed 10~(-12) Pa m~3 s~(-1) m~(-2) and MG>>MG＋CP ≈ OMG ≈ OMG＋CP was obtained for these rates. The outgassing rates of the OMG and the OMG＋CP were almost same with lowest outgassing rate in previous studies.