## 1 Literature Review  
In the implementation of the currently ongoing 4 th Industrial Revolution, ensuring the surface quality of manufactured parts with a fine surface is becoming increasingly important [1]. According to researchers, from a tribological perspective, the reliability and durability of machine parts depends on the result of the manufacturing process and the surface structure formed on the part [2]. The structure of the formed surface affects the wear and fatigue strength of the part [3]. After turning and milling, machined parts often require additional finishing operations, such as grinding and burnishing. During the burnishing process, the surface of the workpiece undergoes cold-plastic deformation. Burnishing can be implemented with burnishing tools operating on different principles, mainly ball burnishing or burnishing tools operating on the sliding friction principle. As a result of burnishing, the surface roughness of the machined part decreases and the surface layer becomes harder [4, 5]. The burnishing process can be performed on various machine tools, including conventional universal lathes and relatively modern NC and CNC machines [6, 7]. Diamond burnishing is a machining process similar to turning; however, it is a chipless, plastic process [8]. Many studies focus on the development of the burnishing technology, with particular attention to the optimization of surface quality, wear resistance, microhardness, and residual stresses. They deal with the burnishing of workpieces of an increasing range of material qualities, such as aluminum alloys [9; 10; 11; 12], titanium and its alloys [13; 14; 15], magnesium and its alloys [16; 17], Inconel [18; 19; 20], AISI 316L stainless steel [21; 22; 23], AISI 304 chromium-nickel austenitic stainless steel [24; 25; 26] chromium alloys [27; 28; 29; 30; 31; 32; 33], and bronze [34]. The material quality of the burnishing tool is often polycrystalline diamond [27; 35; 36; 37; 38; 39]. The methodology of diamond burnishing research is also diverse. The Artificial Neural Network (ANN) method is increasingly used for the analysis of diamond burnishing [28; 40; 41]. The full experimental design methodology [42; 43; 44] and [PERSON]'s method [45; 46; 47] are still commonly used methods. [PERSON] et al. [7], [PERSON] et al. [48], and [PERSON] et al. [49] have used ANOVA analysis in their research, and the finite element method has been used effectively in research [12; 50; 51; 52; 53]. In terms of implementation method, two main areas can be observed in the field of burnishing: ball burnishing and sliding friction burnishing. Of course, there are several other burnishing methods or special tools, such as roller burnishing [9; 40; 52; 54; 55]. Ball burnishing has been studied by [PERSON] et al. [10], [PERSON] and [PERSON] [16], [PERSON] et al. [56], [PERSON] et al. [57], and [PERSON] et al. [58]. [PERSON] et al. [10] applied two-dimensional ultrasonic surface burnishing to produce gradient nanostructures in aluminum alloys and to improve wear resistance. Their research on two-dimensional ultrasonic surface peening (2D-USBP) in aluminum alloys was aimed at producing gradient nanostructures and improving wear resistance. The multi-ball burnishing tool, operating under the synergistic effect of ultrasonic vibration and machining pressure, causes plastic deformation on the surface of aluminum alloys. The heat generated during deformation and convective heat transfer reaches a dynamic equilibrium, which enables quasi-isothermal processing conditions. According to their results, 2D-USBP creates a gradient nanostructure with a thickness of about 660 \(\upmu\)m on the surface of the specimen. The surface hardness of the burnished samples reached 120 HV, which is 60% higher than that of the original samples. According to the wear test results, there was a significant increase in wear resistance on the burnished samples.