|
FGH95 is one of difficult-to-cut nickel-based powder metallurgy (PM) superalloys which are commonly used in
advanced turbo-engines. Firstly, this paper presents an orthogonal design experiments to study the cutting force and
cutting temperature variations in the end milling of FGH95 with two kinds of coated carbide tools. It is found that AlTiN
coated solid carbide end mill is suit for machining FGH95 nickel-based powder metallurgy superalloy. Experimental
results show that with the increase of cutting speed, radial depth of cut, feed rate, there is a growing tendency in cutting
forces. Among the cutting condition parameters, cutting speed has the greatest influence on cutting forces, especially
when cutting speed exceeds 55m/min. With the increase of cutting speed and radial depth of cut, cutting temperature
increases. However the cutting temperature decreases slightly as the increasing of feed rate. Reason for temperature
variations is investigated in this paper. Secondly, tool wear mechanism in end milling of FGH95 is analyzed. It is shown
that chipping on cutting edge is the most dominate wear mechanism which dominates the deterioration and final failure
of the coated carbide tools. Thirdly, the machined surface topography is measured with white light interferometer and
Super depth digital microscope. Based on the measurement, it is found that better surface roughness and waviness are
obtained with using AlTiN coated carbide tools than by TiAlN/TiN/TiAlN coated ones.
|
