《China Foundry》
Title:Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties
Author:*Gui-quan Wang1, Zhuo Xu1, Zhong-li Liu1, Xiang Chen2, 3, and Yan-xiang Li2, 3
Address: 1. School of Nuclear Equipment and Nuclear Engineering, Yantai University, Yantai 264005, Shandong, China; 2. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China; 3. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084, China
Key words:compacted graphite iron; brake disc; thermomechanical properties; thermal fatigue; wear
CLC Nmuber:TG143.5
Document Code:A
Article ID:1672-6421(2024)03-248-09
Abstract:
The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake discs. In this work, the thermal fatigue and wear of compacted graphite iron brake discs were investigated, aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical properties. Compacted graphite iron brake discs with different tensile strengths, macrohardnesses, specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of ferrite. The peak temperature, pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction tests. The morphology of thermal cracks and 3D profiles of the worn surfaces were also discussed. It is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties. A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue resistance. Oxidization of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal cracks. Despite the reduced hardness, increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.