Zhou J.M.,Northwestern Polytechnical University |
Zhou J.M.,The Key Laboratory of Contemporary Design and Integrated Manufacturing Technology |
Gu X.H.,Northwestern Polytechnical University |
Yang F.,Northwestern Polytechnical University |
And 2 more authors.
Advanced Materials Research | Year: 2014
Threshold pressure is a very important parameter for melt alloy successfully infiltrating into the porous preform. However, the precise measurement for threshold pressure is very difficult for the reason that infiltration process is undertaken very fast under extreme elevated temperature and high pressure without effective measuring devices to monitor it. A totally new measuring device was proposed and fabricated, which can be used to monitor the infiltration process "visually" and measure the threshold pressure directly at the same time. The infiltration speed can be controlled by adjusting the gas flow speed. The infiltration behavior of melt AZ91D alloy in Al2O3sf preform was researched at temperature of 800°C and pressure of 0.6 MPa. The optimized gas velocity was controlled at 25L/min. The degree of vacuum of the infiltration cavity was set 30kPa in experiments. The volume fraction of Al2O3sf was 10%. Under these conditions, the threshold pressure of melt AZ91D alloy into porous Al2O3sf preform was found to be related with vacuum degree in infiltration chamber, and it was about 30 kPa. © (2014) Trans Tech Publications, Switzerland.
Liu W.,The Key Laboratory of Contemporary Design and Integrated Manufacturing Technology |
Liu W.,Northwestern Polytechnical University |
Wan X.,The Key Laboratory of Contemporary Design and Integrated Manufacturing Technology |
Wan X.,Northwestern Polytechnical University |
And 6 more authors.
Advanced Materials Research | Year: 2013
The orthogonal experiment is processed for high-speed milling superalloy GH4169 with TiAlN coated carbide inserts. The empirical formula of the surface roughness is acquired by using Genetic Algorithm method. On the basis of this formula, studying the absolute sensitivity and relative sensitivity of surface roughness for milling speed, depth of cut and feed; The results showed that in the process of high-speed milling of high-temperature alloy GH4169, Surface roughness is most sensitive to the change of milling feed; change of milling depth take second place and milling speed is the least sensitive. © (2013) Trans Tech Publications, Switzerland.