Experimental Research on Surface Quality of Titanium Rod Turned by Wire Electrical Discharge Turning Process

Area of Science:

• Materials Science and Engineering
• Manufacturing Processes
• Surface Engineering

Background:

• Miniature cylindrical titanium bars (MCTB) present machining challenges due to their material properties.
• Achieving high surface quality is critical for the performance and longevity of micro-components.
• Wire Electrical Discharge Turning (WEDT) is a viable but complex process for micro-machining.

Purpose of the Study:

• To investigate and optimize the surface quality of MCTB produced via WEDT.
• To identify the key WEDT parameters influencing surface roughness.
• To achieve a significant reduction in mean roughness depth (Rz) through optimization.

Main Methods:

• Utilized a zinc-coated wire (250 µm diameter) for WEDT.
• Employed a Box-Behnken design (BBD) of Response Surface Methodology (RSM) with 17 experimental runs.
• Applied Grey Relational Analysis (GRA) for multi-objective optimization of WEDT parameters.

Main Results:

• Spark duration (Ton) was identified as the most influential parameter on surface roughness (Rz).
• Optimized WEDT parameters (Ton-0.9 µs, SV-30 V, DOC-0.35 mm) yielded a minimum Rz of 7.42 µm.
• Achieved a 37% reduction in surface roughness (Rz) compared to baseline conditions.
• Favorable tribological characteristics were observed in the optimized MCTB.

Conclusions:

• The study successfully optimized WEDT for enhanced surface quality of MCTB.
• The developed methodology offers a significant improvement over previous research in micro-turning titanium.
• Findings are applicable to micro-turning of various difficult-to-machine materials, enhancing component performance.