Study of the Machinability of an Inconel 625 Composite with Added NiTi-TiB2 Fabricated by Direct Laser Deposition

Abstract

This work studies the process feasibility of milling a metal-matrix composite based on Inconel 625 with added NiTi-TiB2 fabricated by direct laser deposition. The composite is intended for manufacturing turbine blades and it has strength characteristics on par with those of Inconel 625. However, the addition of TiB2 has improved its heat and wear resistance. This material is new, and its machinability has not been studied. The new composite was milled with end mill cutters, and recommendations were worked out on the cutting speed, feed per tooth, cutter flank angle, as well as depth and width of milling. The wear of cutter teeth flank was more intense. After the flank wear land on the back surface of a tooth had reached 0.11–0.15 mm, there was a sharp increase in the forces applied which was followed by brittle fracture of the tooth. Milling at a speed of 25 m/min ensured 28 min of stable operation. However, afterwards the critical wear value of 0.11 mm was quickly approached at a cutting speed of 50 m/min, and critical wear followed after 14 min. Dependencies of the cutting forces vs. time for all the selected cutting speeds and throughout the entire testing time period have a tendency to increase, which indicates the influence of cutter wear on the cutting forces. It was found that the durability of the cutters increases with an increase in the milling width and a decrease in the milling depth.

Analysis of Machinability on Properties of Inconel 718 Wire and Arc Additive Manufacturing Products

“…Another property that, along with the hardness, is quoted as having a direct effect on the cutting forces is the tensile strength. It is known that the high values for both hardness and tensile strengths are associated with low machinability, which affects the cutting forces [42]. As explained previously, the AMS5662 presents higher tensile and yield strength for this kind of property.…”

An In-Depth Exploration of Unconventional Machining Techniques for INCONEL® Alloys

“…Arlyapov et al [ 94 ] examined a metal–matrix composite (MMC) milling process based on INCONEL ® 625 with added NiTi-TiB2. Parameters such as s , feed per tooth ( f z ), axial depth ( a e ) and a p are optimised, while VB max and R a were minimised.…”

“…Other machining characteristics, including burr width and Fc, also demonstrated improvements in both MQL and EFC environments. Scanning electron Arlyapov et al [94] examined a metal-matrix composite (MMC) milling process based on INCONEL ® 625 with added NiTi-TiB2. Parameters such as s, feed per tooth (f z ), axial depth (a e ) and a p are optimised, while VB max and R a were minimised.…”