INVESTIGATION OF THE METHOD OF THERMAL FRICTION TURN-MILLING OF HIGH STRENGTH MATERIALS

An analysis of the state of the matter of the manufacture of parts such as bodies of revolution has shown that there is a problem of turning processing by turning large, long parts, connected with increasing productivity and processing quality, as well as reducing the costs of turning operations. To solve this problem, the authors propose a resource-saving combined method for treating external cylindrical surfaces by thermal friction turn-milling. Experimental studies were performed on the processing of the outer cylindrical surface using a special friction cutter made of non-instrumental material. The results showed that with thermal friction turn-milling, it is possible to achieve Ra = 1,0 mcm. The process of chip formation was also investigated and the formation of a retarded layer was established, which protects the surface of the friction cutter from wear. Optimum values of cutting conditions for processing by thermal friction turn-milling of steel 30HGSA.

Cutting Forces during Inconel 718 Orthogonal Turn-Milling

Inconel 718 is a material often used in the aerospace and marine industries due to its properties and ability to work in harsh environments. However, its machining is difficult, and therefore methods are sought to facilitate this process. One of such methods is turn-milling. This paper presents the forces during orthogonal turn-milling of the Inconel 718 alloy. In this machining, both the side and the end edge are involved in the material removal, which causes the tool to be more loaded. The forces during turn-milling can be up to 50% higher than in the case of milling, which causes damage to the tool. Tool wear during machining has a significant impact on the values of the cutting force proportional coefficients. In the case of the tested material, it is important to take it into account when creating cutting force models.

Empirical study on ultrasonic assisted turn-milling

Turn-milling process has been paid attention in order to be used in multi-task machining processes. Moreover, looking for new machining techniques aimed at reducing cutting force is of important. Reducing cutting force in machining processes has the benefits of extending tool life and improving surface quality. One of the new concepts for reducing the cutting force is applying ultrasonic vibration. In this paper, effects of ultrasonic vibration under different machining parameters in turn-milling process of Al-7075 alloy will be investigated. In this order, a special mechanism was designed to apply ultrasonic vibration during machining process. Ultrasonic vibration exertion on the tool reduced cutting force and surface roughness up to 75% and 35%, respectively. Also tool rotational speed increment induced cutting force and surface roughness increment. In addition, tool feed rate and workpiece rotational speed increment caused cutting force and surface roughness increment. Although, feed rate was more influential.

Optimization of turn-milling process in roughing and finishing regimes: Trade-off between productivity, cutting force and surface integrity

Turn-milling is a hybrid machining process which used benefits of interrupted cutting for proceeding of round bars. However, number of controllable parameters in the hybrid process is numerous that makes optimizing the process complicated. In the present study, an optimization work has been proposed to investigate the trade-off between production rate and cutting force in roughing regime as well surface roughness and tensile residual stress in finishing regime. Number of 43 experiments based on response surface methodology was designed and carried out to gather required data for development of quadratic empirical models. Then, the adequacy and importance of process factors were analyzed using analysis of variances. Finally, desirability function was used to optimize the process in rough and finish machining regimes. The obtained results showed that selection of eccentricity and cutter speed at their maximum working range can effectively enhance the quality characteristics in both the roughing and finishing regimes.