## 1 Introduction
The results indicated that the SLM-processed alloy showed superior wear performance under dry sliding conditions, but experienced more wear under wet conditions. However, no in-depth analysis of the wear mechanisms of the alloy in dry and lubricated conditions was conducted, and the effects of varying loads and speeds on the friction and wear behavior of the alloy have not been investigated. [PERSON] et al. [18] investigated the wear resistance and biocompatibility of Co-Cr dental alloys, produced using the casting and SLM methods. The aim of their study was to compare the suitability of SLM versus traditional casting for producing dental Co-Cr alloys. The microstructure, surface composition, mechanical properties, and wear resistance of the alloys were evaluated. The authors conducted the sliding wear tests using a ball-on-disk tribometer with a silicon nitride ceramic ball as the counter material. Their results showed that SLM alloys exhibited shallower wear scars and less wear debris compared to the cast alloys. However, they only applied a constant load of 5N at a constant rotational speed and did not investigate the effects of load and sliding speed on the coefficient of friction and wear rate. They also did not investigated the wear mechanisms of the alloy, and the duration of their tests was only 30 min. Another limitation of their study was that it was only conducted in dry contact, and the effect of lubrication was not investigated. [PERSON] et al. [19] analyzed the effect of post-process heat treatment on the hardness, microstructure, and sliding wear behavior of Co-28 Cr-6 Mo alloy manufactured by SLM. The dry sliding wear behavior of the as-built and heat-treated Laser-PBF Co-28 Cr-6 Mo alloy was studied, with the conventional wrought alloy used as a benchmark. An AISI 52100 steel cylinder was used as the counter surface, and it was observed that the as-built LPBF alloy displayed greater wear resistance than the conventional wrought alloy. The optimized aging treatment significantly altered the as-built Laser-PBF microstructure, improved the alloy's hardness, and generally improved its friction and wear behavior. However, the sliding wear tests were only conducted in dry contact, with no variations in the sliding speed. As can be seen from the above literature review, a systematic study has not been conducted yet to investigate the tribological performance of the PBF-LB/M Co-Cr-Mo alloy under different working conditions, and the wear morphology and mechanisms have not been explored in detail. Therefore, in this paper, we are presenting the results of sliding wear tests of the PBF-LB/M Co-28 Cr-6 Mo alloy under a range of applied loads, sliding speeds, and lubricants. The friction and wear behavior of the Co-28 Cr-6 Mo alloy is compared with the samples produced by the traditional casting process. In order to investigate the wear mechanisms and chemical compositions of the wear tracks, we employed scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX). The findings obtained from this study can be utilized as a resource for selecting suitable operating conditions to minimize wear in PBF-LB/M Co-28 Cr-6 Mo alloy applications.