Phenolic resins have been widely used as a binder for friction materials. Increased performance requirements have exceeded the capabilities of standard phenolic resins. Various modified phenolic resins have been developed with proven capabilities and performance levels. The impact on the environment and work place must also be considered when developing new products. In addition to improved performance, new phenolic resins for friction applications should also be improved to address environmental and work place issues. In order to achieve further improvement, fundamental studies, such as morphology, are needed.
An EPMA (Electron Probe Micro Analyzer) is useful to identify elements, while former investigations have developed the technology to identify some ingredients in friction materials. However, it has been impossible to show phenolic resin in friction materials since they contain many other ingredients also made from carbon.
Porosity also plays a great role in final properties of friction materials. Therefore, it is important to map porosity in friction materials in addition to mapping phenolic resin.
This paper will review the followings:
Technology to show presence and distribution of phenolic resin in friction materials.
Map phenolic resins in friction materials.
Technology to show presence and distribution of porosity in friction materials.
Map the porosity in friction materials.
The relationship between the distribution of phenolic resin, porosity, and physical properties.