Research on the cold plasma jet assisted cutting of Ti6Al4V

Abstract

A long, quasi-homogeneous cold plasma jet was generated through a homemade cold plasma jet generating device. Friction-wear test and assisted cutting of Ti6Al4V were studied under air, nitrogen, and nitrogen cold plasma jet (NPJ) atmospheres. The friction coefficient under nitrogen jet was small, and the wear appearance was smooth at lowspeed friction. At high-speed friction, the friction coefficient under NPJ was the smallest, which declined by 70 % compared with that under air atmosphere. The scratches and adhesive traces on the friction surface were the lightest as well. The lubrication and cooling effects were not evident under low-speed cutting, whereas the NPJ enabled the radial force Fy and the average flank wear width VB to decrease by nearly 40-47 % respectively under high-speed cutting compared with the ones under air atmosphere. Results show that the NPJ assisted cutting has little influence on the surface roughness, residual stress, and work hardening of workpieces, while the machinability of Ti6Al4V can be effectively improved.

Field-assisted machining of difficult-to-machine materials

“…The friction coefficient was nearly 60% lower than that in air and the graphitization temperature of the diamond was increased by 38.9% by NPJ treatment. Liu et al [170] conducted a theoretical and experimental study on the PAC of Ti6Al4V. The results indicated that the machinability of Ti6Al4V could be remarkably improved with the assistance of a cold plasma jet.…”

A critical review on the chemical wear and wear suppression of diamond tools in diamond cutting of ferrous metals

“…The material is sprayed directly into the cutting zone so that chemical affinity between the toolworkpiece interface is reduced. Furthermore, the plasma acts as a lubricant, thus reducing the built-up edge and decreasing the thermal generation in the cutting zone, as shown in figure 32 [29,40,103,104].…”

“…The Fe x C y N z is then adsorbed into the workpiece surface. During the cutting process, the complex thermal actions between the toolworkpiece contact interface also induce the reactive ions to generate new compounds, such as Fe(CO) 2 (NO) 2 and Fe (2/3/4) N, as shown in equations (3) and (4) [105].…”

“…Specific process methods on reducing cutting temperature, reducing contact time, pre-treatment of material surface, etc [10,11] were then proposed. The processing technologies for reducing chemical activity between the tool and the workpiece materials include: gas protection cutting [19], cold plasma assisted cutting [29,30], carbon particle protection cutting [31], liquid nitrogen cooling cutting [20], ultrasonic vibration assisted cutting [21], and highly intermittent cutting [32]. Processes that avoid direct contact between the tool and the substrate include: diamond surface coating [23], surface nitriding/phosphorus in workpiece material [24,33,34], as shown in table 1.…”