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The 304 austenitic stainless steel is used in a wide range of important industries such as industrial, food, medical, and furniture decoration, seeming the most widely used chromium-nickel stainless steel, but which machinability proves very poor, being a typical difficult cutting material. The tool wear phenomenon is very serious in the process of cutting and is not easy to acquire the splendid machining quality. For this reason, the ultrasonic vibration is introduced into turning to realize ultrasonic vibration-assisted turning (UAT) to solve the above problems in this study. This paper first proves that the ultrasonic vibration has a certain inhibitory effect on the tool wear by theoretical and simulation methods. Then, the influence of technological parameters on the tool wear is studied by experiments. The results show that there is an optimal range of the ultrasonic amplitude and the cutting speed for the UAT, and which has a significant inhibitory effect on the tool wear when the technological parameters are selected properly. The tool wear of conventional turning (CT) is more serious under the same technological parameters. In addition to the abrasive wear and the adhesive wear, the deformation and the collapse also occur, accompanied by obvious sticking substances, which reduce the service life of the cutting tool greatly and has a certain impact on the machining efficiency and the cost. Furthermore, the UAT can also achieve better-machined surface quality under the condition of technological parameters with the less tool wear. [ABSTRACT FROM AUTHOR]

When processing difficult-to-cut materials, conventional turning (CT) typically suffers from the problems of large cutting force, difficult chip removal, and serious tool wear, resulting in deteriorated processing quality, reduced processing efficiency, and increased processing costs. In addition, special-purpose machine tools used for ultrasonic machining exhibit disadvantages, such as narrow application scope, high manufacturing cost, and poor universality; thus, they are not conducive to being popular in actual production and processing. Accordingly, this study analyzed the characteristics of ultrasonic wave, the mechanism of ultrasonic vibration-assisted turning (UAT), and the formation of a machined surface in UAT. Moreover, the machining system of UAT was established. This system applied an ultrasonic wave vibration device to an engine lathe to meet the requirements of vibration cutting in actual production. Simultaneously, Inconel 718, a typical and widely used difficult-to-cut material, was selected for the experimental study. The machining effect of UAT was analyzed in detail, including surface roughness, surface topography, and chip shape. Results indicated that ultrasonic amplitude, cutting speed, depth of cut, and feed rate exert considerable influences on the machining effect. UAT can achieve this effect, which is difficult to realize via CT, under the condition of a reasonable selection of technological parameters. This research can provide theoretical support and experimental basis for the development and practical application of UAT. [ABSTRACT FROM AUTHOR]