High-strength gears produced by powder metallurgical processes

采用粉末冶金工艺生产的高强度齿轮

• 批准号: 200616644
• 负责人: Professor Dr.-Ing. Christoph Broeckmann
• 金额: --
• 依托单位: Werkzeugmaschinenlabor - WZL
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/200616644?language=en
• 关键词: strength; gears; produced; powder; metallurgical

For manufacturing of gears several process chains can be applied. A process chain with high resource efficiency is a powder metallurgical production, which is composed by die pressing, sintering, densification rolling and case hardening. Manufacturing resource employment is minimized by energy efficient manufacturing and low material usage. Surface densified PM gears with a comparable strength have a 10% reduced weight compared to fully dense gears. This also contributes to resource efficiency.The proposed research project targets an improved material usage and a load suitable boundary layer for optimization of part design. Hence the project directly addresses the objectives of the Priority Program Resource efficient machine elements (SPP 1551)The objective of this project is the increase of resource efficiency of gears by a holistic optimization of the powder metallurgical gear production. For that an optimization of tooth root geometry and surface density profile by prediction of tooth root strength will be performed. Therefore, different density profiles are considered for the determination of the optimal tooth root geometry and the prediction of its strength. For the latter, the methodology developed in phase 1 is used. By comparison of experiment and theoretically determined values the methodology to predict tooth root endurance strength is verified. Furthermore, the potential of variable tooth geometries for powder metallurgical manufactured, surface densified gears is evaluated. It will be investigated, which tooth geometries are suitable for surface densification by rolling. Furthermore, the potential of shot peening as an alternative densification process is evaluated. Shot peening offers the possibility to densify geometries, which are not rollable. Additionally, the methodology to predict tooth root endurance strength is extended to predict the rolling strength as well. The local comparison of load and strength will be extended to Hertzian contact for a material with profile of density and carbon content.The cooperation within Priority Program Resource efficient machine elements (SPP 1551) will be used to apply chosen methods of other projects to generate boundary layers onto the process chain to produce PM gears. Suitable processes for generating boundary layers are to be identified and investigated. This shall result in a further increase of resource efficiency during the gears usage. Comparison of strength and process chains will result in a verification of resource efficiency.

对于齿轮的制造，可以采用几种工艺链。资源效率高的工艺链是由模压、烧结、致密化轧制和淬火组成的粉末冶金生产。通过节能制造和低材料使用，将制造资源的使用降至最低。表面致密的粉末冶金齿轮具有相当的强度有一个10%的重量减轻相比，完全致密的齿轮。这也有助于提高资源效率。提出的研究项目的目标是改善材料的使用和载荷合适的边界层，以优化零件的设计。因此，该项目直接解决了优先计划资源高效机器元件（spp1551）的目标，该项目的目标是通过粉末冶金齿轮生产的整体优化来提高齿轮的资源效率。通过对齿根强度的预测，对齿根几何形状和表面密度轮廓进行优化。因此，在确定最佳牙根几何形状和预测其强度时，需要考虑不同的密度轮廓。对于后者，将使用阶段1中开发的方法。通过实验值与理论值的比较，验证了牙根持久强度预测的方法。此外，对粉末冶金制造的表面致密齿轮的可变齿形的潜力进行了评估。它将被调查，哪些齿的几何形状是适合的表面致密化轧制。此外，还评估了喷丸强化作为一种替代致密化工艺的潜力。喷丸强化提供了致密的几何形状，这是不可滚动的可能性。此外，还将齿根持久强度预测方法推广到轧制强度预测中。载荷和强度的局部比较将扩展到具有密度和碳含量剖面的材料的赫兹接触。优先计划资源高效机械元件（spp1551）内的合作将用于应用其他项目的选定方法，在工艺链上生成边界层，以生产PM齿轮。要确定和研究产生边界层的合适过程。这将导致在齿轮使用过程中进一步提高资源效率。强度和工艺链的比较将导致对资源效率的验证。