Experimental Study on the Dry Drilling Nickel-Based Superalloy of CrAlYN Coated Carbide Bit.

Nickel-based superalloy is regarded as one of the materials with the poorest cutting and drilling performance. Additionally, there is much less research on the drilling of it. This paper aims to study the drilling performance of dry drilling nickel-based superalloy with uncoated and CrAlYN coated carbide bit. First of all, the primary and secondary factors influencing the machining performance of dry drilling nickel-base superalloy uncoated carbide bit were explored through an orthogonal test. Secondly, the self-prepared CrAlYN coated carbide drills, and uncoated drills were compared and analyzed from perspectives of service life, drilling force, drilling temperature, drill surface topography, failure mechanism, and machining surface quality. The research results are as follows: the drilling temperature is the primary factor affecting the drilling performance under dry drilling conditions. CrAlYN coating can obviously prolong the service life of tools, reduce the drilling force and drilling temperature, and improve the machining surface quality at lower rotational speeds. Moreover, the coated cemented carbide bit has a similar failure mode to the uncoated cemented carbide bit after the CrAlYN coating falls off in the wear zone of cemented carbide bit, which is mainly bonding wear on the rear tool surface and the front tool surface.