Shucai Yang

Wear characteristics of cemented carbide tool in dry-machining Ti-6Al-4V

ABSTRACT In machining titanium alloys, due to the low thermal conductivity and high chemical activity of titanium alloys, tool wear is serious and processing efficiency is very low. To avoid the effects of impurities, which were brought by the cutting fluid, the uncoated cemented carbide tool (WC-Co), which was suitable for cutting titanium alloys, was used for the experiments of dry-turning titanium alloy Ti-6Al-4V. A scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectrometer (EDS) was used to analyze tool wear mechanism. Based on analyzing the friction characteristic of tool–chip interface, tool wear mechanism was also studied and a physical evolution model of tool wear was established. The results showed that there existed serious adhesion, diffusion and oxidation at tool–chip interface and increasing cutting speed accelerated their occurrence. The physical evolution of tool wear behavior can reflect the loss process of tool material very well.

Study on the influence of meso-geometrical features on milling force in precision machining of titanium alloy

ABSTRACT Titanium Alloy is a typical material difficult to be processed for its characteristics of low thermal conductivity, and high chemical activity, which result in tool wear and the poor quality of the machined surface. In order to solve the problems existing in the processing of Titanium Alloy, considering the tool edge, micro-texture is implanted into the cemented carbide ball end milling cutter. The article analyzes the influence law of micro-texture and the tool edge radius of ball end milling cutter on mechanical properties of Titanium Alloy, establishes and verifies a mechanical predictive model of milling Titanium Alloy with ball end milling cutter surface based on the effect of micro-texture and the tool edge. Finally, with regard to the minimum cutting force as the target, the article uses genetic algorithm to optimize meso-geometrical features parameters of the cemented carbide ball end milling cutter. The article also provides the foundation for efficient and high-quality processing of Titanium Alloy.

Models of the relationship among geometric parameters and anti-friction mechanism of micro-texture ball-end milling cutter

Researches on the effect of the micro-texture on the cutting performance and the life of cutters are mostly aimed at turning cutters, but there are few researches on the ball-end milling cutter. On the basis geometry of the micro-texture, the distribution and the relationship among the geometric parameters of micro-pits are studied. A mechanical characteristic model of machining titanium alloy with the micro-texture ball-end milling cutter is established. Optimal parameters of the micro-texture are determined by the simulation. By the test of machining the titanium alloy with the micro-texture ball-end milling cutter, anti-friction properties, the influence laws of the micro-texture diameter on forces, and area occupancy on the tool wear are studied. This article provides a theoretical reference for determining the location of the micro-texture on ball-end milling cutter and selecting texture parameters reasonably. The anti-friction mechanism of the micro-texture is revealed by the theory, which provides a theoretical basis for the efficient processing of titanium alloy.