Investigating drilling efficiency: a study on indexable centerless drilling of Ti-6Al-4 V alloy

• Published in: International journal of advanced manufacturing technology Vol. 133; no. 5-6; pp. 2157 - 2169
• Main Authors: Zahoor, Sadaf, Ehsan, Sana, Raza, Syed Farhan, Khan, Atif Qayyum, Anwar, Saqib, Ali, Ahad
• Format: Journal Article
• Language: English
• Published: London Springer London 01-07-2024; Springer Nature B.V
• Subjects: Aerospace industry; Boreholes; CAE) and Design; Carbide tools; Computer-Aided Engineering (CAD; Cooling; Cutting tool materials; Cutting wear; Drilling; Engineering; Feed rate; Industrial and Production Engineering; Inserts; Machining; Mechanical Engineering; Media Management; Original Article; Strength to weight ratio; Surface properties; Surface roughness; Tensile strength; Thermal conductivity; Titanium alloys; Titanium base alloys; Tool life; Tool wear; Vanadium; MQL; Indexable centerless inserts; Scanning electron microscopy (SEM); Titanium alloy (Ti-6Al-4 V); Surface topographic
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-024-13760-z

Titanium alloy Ti-6Al-4 V holds a prominent status within the aerospace sector owing to its remarkable strength-to-weight ratio. However, its low thermal conductivity and high tensile strength present machining obstacles, resulting in elevated tool temperatures and mechanical stress. In aircraft manufacturing, drilling is essential, yet using solid carbide drills conventionally leads to considerable tool wear. Prior investigations aimed at enhancing tool longevity have explored diverse cutting methodologies, spanning from flood cooling to minimum quantity lubrication (MQL). Despite these efforts, persistent challenges endure. Therefore, this study introduces an innovative approach, leveraging titanium aluminum nitride (TiAlN)-coated indexable centerless inserts to bore holes in Ti-6Al-4 V under three distinct cutting conditions: dry, flood cooling, and MQL. These conditions are scrutinized across varied feed rates (60 mm/min, 100 mm/min, and 120 mm/min) with a fixed spindle speed of 1200 rpm. The study’s primary focus is on key output parameters, including surface roughness (SR), tool life, and cutting temperature. From the parametric and surface topographic analysis, the findings reveal that under the flood cutting approach with a 60-mm/min feed rate, the indexable inserts excelled when drilling Ti-6Al-4 V. This combination delivered a better surface quality (Ra = 1.66 µm), extended tool life (27,814.27 mm
3
material removed and 18 holes drilled), and lower cutting temperature (881°F). Additionally, scanning electron microscopy (SEM) analysis corroborates that most common types of wear observed were abrasion, delamination, cracking, and edge fracture.