Tribosystems for cold forming processes based on volatile lubricants and laser structured surfaces

斯图加特大学金属成形技术、界面工艺工程和等离子体技术以及激光技术研究所提交的拟议研究项目将为冷成形工艺带来全新的摩擦学系统。这种摩擦系统应针对特定的表面压力水平和通过在工具侧使用激光处理表面来消除摩擦剪切应力而开发，该研究项目的第一阶段包括对固态或液态挥发性润滑介质特性的物理和知识导向的基础研究（（N2或CO2）在先前激光结构化的半成品工具表面上。首先，应在示范性实验室试验（拉带试验和高压灭菌）上完成调查。随后的供资期应涉及对真实的板材和大块金属成形工艺及其在半成品零件或工具上的应用的研究。因此，该项目的长期目标是提供一种经过验证的摩擦学系统，该系统基于激光结构化表面，在成型过程之前或过程中进行润湿，中间体在过程后挥发而没有任何残留物。因此，斯图加特大学研究所合作的科学声明涉及该计划的宣布，该计划联合开发了用于真实的摩擦条件下金属成形技术的高性能摩擦系统，随后将对板材和大块金属成形的一些示例性工艺进行表征。所获得的科学知识预计在金属成形技术的改进过程控制领域的新的，更合适的拓扑结构的工具表面，以及对分布和润湿机制在挥发性润滑中间体的零件和工具之间的摩擦的更深入的了解。初步测试表明，固态CO2的应用显著降低了摩擦，可以作为一种临时作用、无残留和环境中性（CO2取自空气）的润滑剂。

The proposed research project submitted by the Institutes for Metal Forming Technology, Interfacial Process Engineering and Plasma Technology as well as Laser Technologies belonging to University of Stuttgart will lead to entirely novel tribological systems for cold forming processes. Such tribosystems shall be developed for specific surface pressure levels and variably acting friction shear stresses by using laser prepared surfaces on the tool side, and a solid, liquid or gaseous volatile intermediate.The first time phase of the research project contains physical and knowledge-oriented fundamental research on characterization of volatile lubricating media applied in solid or liquid state ((N2 or CO2) on previously laser structured semi-finished tool surfaces. At first, the investigations shall be accomplished on exemplary laboratory tests (strip drawing test and autoclav). Subsequent funding periods should deal with investigations on real sheet and bulk metal forming processes and its application on semi-finished part or tool. Long-term goal of the project is thus to provide a validated tribological system, based on laser structured surfaces, which were wetted just before or during forming process, with an intermediate that volatilizes without any residues after the process. The scientific claim of the collaboration of the Institutes of the University of Stuttgart therefore is referred to the announcement of this program in joint development of a high performance of such tribosystems for metal forming technology under real friction conditions, which later shall be characterized for some exemplary processes of sheet and bulk metal forming. The gained scientific knowledge is expected in the field of modified process control in metal forming technology on novel, more suitable topologies of the tool surfaces as well as on a deeper insight of distribution and wetting mechanisms in interstice between part and tool of volatile lubricating intermediates. Preliminary tests have shown that the application of CO2 in solid state reduces the friction in a significant manner and can work as a temporarily acting, residue-free and environmentally neutral (CO2 is taken from air) lubricant.