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技术研究所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。通过在工具侧使用激光制备表面和固体、液体或气体的挥发性中间体，此类摩擦系统应针对特定的表面压力水平和可变作用的摩擦剪应力而开发。研究项目的第一个时间阶段包含以物理和知识为导向的基础研究，即在以前的激光构造的半成品工具表面上应用于固体或液态((N2或CO2))的挥发性润滑介质的表征。首先，调查应在示范实验室试验(拉拔试验和自动测试)上完成。随后的资金期应涉及对实际板材和大宗金属成形工艺及其在半成品零件或工具上的应用的调查。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表面，在成形过程之前或过程中被湿润，中间体在成形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主张指的是该计划的宣布，该计划联合开发这种摩擦系统在真实摩擦条件下的高性能金属成形技术，稍后将描述一些板材和块状金属成形的示范过程。期望在金属成形技术中的改进工艺控制领域获得新的、更合适的刀具表面形貌的科学知识，以及对挥发性润滑中间体在零件和刀具间隙中的分布和润湿机理有更深入的了解。初步试验表明，在固体状态下应用二氧化碳可以显著降低摩擦，并且可以作为临时作用、无残留物和环境中性(二氧化碳从空气中提取)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.