Large aperture step hole is more common in titanium alloy structural parts

titanium alloy difficult to machine leads to its poor machining quality

low efficiency

the helical milling hole not only has the advantages of small cutting force

low cutting temperature

good surface quality

but also can make holes at one time. In this paper

aiming at the characteristics of different quality and dimensional accuracy requirements of large aperture step holes of titanium alloy

single-factor experiments were carried out on the Φ13.5 mm holes and Φ18 mm holes of the step holes

and the influence of the three factors on the axial force

surface roughness and aperture of the helical milling hole was studied

the helical hole making processing parameters of the two holes were optimized

and the optimization parameters were used to machine the large aperture step holes of titanium alloy. The results show that the pitch has the greatest influence on the axial force and surface roughness

the main influencing factor of the aperture is the tangential feed per tooth and pitch

and a helical milling hole can machine a high-quality and high-dimensional accuracy of large aperture step hole of titanium alloy.