The brake noise is one of the highest incidences of complaints from OEM’s customers, causing problems such as passenger disappointment and warranty costs. With the improvement of the comfort and soundproofing of the automobile, the brake noise has increased customers’ concerns, making them believe that it is a component defect, although it is fulfilling its functions. One of the factors that can attenuate the vibration in a structure is the increase in its inherent damping capacity. Therefore, a material capable of dissipating energy of vibrations may minimize noise, vibration and harshness problems in the braking system. In this work, an experimental study of mechanical properties, microstructural analysis and damping capacity was carried out on different nodular cast irons with variation of the Co, Si, RE contents. The research goal is the achievement of the best compromise between the mechanical properties required for the braking system parts and their damping capacity. In spite of the damping capacity and tensile strength that were likely to be mutually exclusive, a simultaneous increase in both was registered for samples with high Si content, comprising different additions of RE, and for samples alloyed with Co. These results seem to be associated with solid solution strengthening of a fully ferritic matrix, combined with nodule density increase.

中文翻译：

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合金元素对制动系统零件球墨铸铁阻尼能力的影响

制动噪音是OEM客户投诉最多的事件之一，引起乘客失望和保修成本之类的问题。随着汽车舒适性和隔音性能的提高，制动噪音引起了客户越来越多的关注，使他们认为这是一个零件缺陷，尽管它正在履行其功能。可以减弱结构振动的因素之一是其固有阻尼能力的提高。因此，能够消散振动能量的材料可以使制动系统中的噪声，振动和粗糙度问题最小化。在这项工作中，对不同球墨铸铁随Co，Si，RE含量的变化进行了力学性能，显微组织分析和阻尼能力的实验研究。研究目标是在制动系统零件所需的机械性能与其阻尼能力之间取得最佳折衷。尽管阻尼能力和拉伸强度可能会相互排斥，但对于含高含量Si的样品（包括不同的RE添加量）和与Co合金化的样品，两者的增加同时出现。这些结果似乎是相关的固溶强化全铁素体基体，同时增加结核密度。