Experimental and simulative investigations on the fatigue behavior of compounds, consisted of Cr-based nitride hard coatings on steel substrate under cyclic impact loads and bending stresses“ (Fatigue)

对由钢基体上的铬基氮化物硬质涂层组成的化合物在循环冲击载荷和弯曲应力下的疲劳行为进行实验和模拟研究（疲劳）

• 批准号: 422784687
• 负责人: Professorin Dr.-Ing. Kirsten Bobzin
• 金额: --
• 依托单位: Institut für Oberflächentechnik (IOT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/422784687?language=en
• 关键词: Experimental; simulative; investigations; fatigue; behavior

PVD (physical vapor deposition) coated tools are subject to cyclic impact forces and superimposed bending loads during their operating time in tribological applications, e.g. in forward cold forging. Impact tests and 4-point bending tests are among the established methods for investigations on the fatigue behavior of PVD coated tools. While tools in technical applications are usually subjected to both stresses, in the literature either the cyclic impact stresses or the bending forces are considered. Furthermore, there are contradictory reports in the literature regarding the influence of PVD coatings on the fatigue strength of the coated tools, since the failure mechanisms under mentioned loadings have not yet been sufficiently investigated. The overall objective of this research project is thus the experimental and simulative investigation of the fatigue behavior of compounds, consisted of (Cr,Al)N hard coatings and steel substrate HS6-5-2C, under both cyclic impact loads and bending stresses. A fundamental contribution to the description of failure mechanisms will be provided in dependence upon the coating properties thickness, morphology, chemical composition and elastic-plastic properties as well as depth-dependent properties indentation hardness, indentation modulus and residual stresses. For this purpose, the coating systems (Cr1-xAlx)N, with x = 0.20; 0.40; 0.60, will be deposited on steel substrate 1.3343 by means of HPPMS (high power pulsed magnetron sputtering). Impact tests will be carried out to investigate the material behavior under cyclic impact forces. 4 point bending tests will be used for cyclic bending loads. The coated steel specimens will be compared with uncoated samples with respect to the fatigue strength under cyclic loading. The fatigue behavior of all variants will be investigated, taking into account the depth dependent properties, by both experimental works at Surface Engineering Institute (IOT), RWTH Aachen University, and simulative studies at Institute for Materials Testing, Materials Science and Strength of Materials (IMWF), University of Stuttgart. A major part of this research project is the analysis of the fatigue behavior and the failure modes of the test specimens after cyclic loading tests. For this purpose, fundamental analyzes will be carried out by means of scanning (SEM) and transmission electron microscopy (TEM). Thus, on the one hand, it will be clarified how the considered coated and uncoated test specimens behave mechanically in the impact and in the 4 point bending tests. On the other hand, the influence of the hard (Cr1-xAlx)N coatings on the fatigue strength of the compound will be investigated. A verification and extension of the findings for further coating systems is planned for a possible third research year.

PVD（物理蒸气沉积）涂层工具在摩擦学应用中的操作时间（例如在前进的冷锻造中。冲击测试和4分弯曲测试是研究PVD涂层工具疲劳行为的既定方法。尽管技术应用中的工具通常都承受两种压力，但在文献中，循环撞击应力或弯曲力都被考虑。此外，文献中有关于PVD涂层对涂层工具疲劳强度的影响的矛盾报告，因为尚未对下述负载下的故障机制进行充分的研究。因此，该研究项目的总体目标是对化合物的疲劳行为的实验和模拟研究，包括（Cr，Al）硬涂层和钢基材HS6-5-2C，在循环撞击负荷和弯曲应力下。依赖于涂层特性，形态，化学组成和弹性塑性特性以及深度依赖性特性压痕硬度，压痕模量和残余应力，将提供对破坏机制描述的基本贡献。为此，涂层系统（CR1-XALX）N，x = 0.20; 0.40; 0.60将通过HPPM（高功率脉冲磁控溅射）沉积在钢基材上1.3343。将进行撞击测试以研究循环影响力下的物质行为。 4点弯曲测试将用于循环弯曲载荷。在环状载荷下，将涂层的钢试样与未涂层的样品进行比较。在Surface Engineering Institute（IoT），RWTH Aachen University的实验工作以及材料测试，材料科学和材料材料的材料科学强度研究所（IMWF）的Sublation Institute（IoT）的两项实验研究，将研究所有变体的疲劳行为。该研究项目的主要部分是对循环加载测试后的疲劳行为和测试样品的故障模式的分析。为此，将通过扫描（SEM）和透射电子显微镜（TEM）进行基本分析。因此，一方面，将澄清所考虑的涂层和未涂层​​的测试样品在撞击和4分弯曲测试中的机械表现。另一方面，将研究硬涂层（CR1-XALX）N涂层对化合物疲劳强度的影响。计划在可能的第三个研究年度对进一步涂层系统的发现进行验证和扩展。