Search Results

Our study focuses on not only how the physical properties of pad matrix strength and porosity depend on the titanates' crystal structure and shape, but also on the chemical properties of the titanates themselves. As a result, it has been found that the reaction that occurs on the friction surface containing titanate and phenolic resin has an influence on the tribological performance of brakes. Our conclusion remains that titanates affect the thermal-reaction of phenolic resins [4] [5]. This study analyzes just what materials are generated by the thermal reaction of the phenolic resin in detail by studying samples with or without Titanate. The results show that the phenomenon of the generation of the char, which has its roots in the decomposition of the phenolic resins, is different between the samples with titanate, and without titanate. Along with pyrolysis products such as phenol monomer and dimer, char is commonly generated during the decomposition of phenolic resins.

Our previous study focused on not only how the physical properties of pad matrix strength and porosity depend on the titanates' crystal structure and shape, but also on the chemical properties of the titanates themselves. As a result, it was found that the reaction that occurs on the friction surface of the titanate and the phenolic resin has an influence on the tribological performance of brakes. Our conclusion was that titanates affect the thermal reaction of phenolic resins. Our newest study uses 1/7-scale dynamometer testing to further investigate the relationship between titanate compounds and phenolic resins. The results make clear that when titanate is added, μ is more stable than when not added. The results of chemical experiments showed that the products of pyrolysis are different when titanate is added or not added. Our conclusion is the property of the products of pyrolysis affects the stability of μ.

Titanates are currently used in friction materials worldwide. This study investigates the effects of titanates in friction materials with Low Steel (LS) formulations. A kind of titanate compound is examined with a LS formulation. Test pieces both with and without the titanate are examined using small rotors of gray cast iron. The frictional performance tests use a 1/7 scale dynamometer. The surfaces and the cross-sections are closely observed using a Scanning Electron Microscopic analyzer. Results of the testing on samples without the titanate suggest that frictional effectiveness is sensitive to the load value especially in high speed braking conditions. A Metal Pick Up (MPU) phenomenon, which is one of the significant problems of friction materials, also occurs. The millimeter-sized picked-up metals consist of micron-sized wear debris of iron. The crystalline transformation of the steel fibers around the picked up metals is investigated.

Titanate compounds are well-known for being widely used in Non-Asbestos Organic (NAO) brake pad formulations. These NAO formulations provide excellent performance in friction stability and a low amount of wear for disc brake pads. In our previous reports, we observed that brake performance in dynamo testing is influenced by a titanate's chemical composition, crystalline structure, and powder properties. We also introduced the thrust test machine as an easy method to evaluate friction materials [1], [2]. In our later research, Otsuka synthesized a new non-fibrous titanate that performs nearly at the same level as fibrous titanates. This new non-fibrous compound contains many pores which form as a result of aggregates of submicron-sized particles; this thereby provides strong fade-proof performance [3].

It is known that titanates widely use materials for the Non-Asbestos-and-Organic formulation; NAO has excellent performance such as stability in friction level and low wear for disc brake pads. In our previous report[1], we presented that those brake performance depends on the chemical composition, crystal structure and powder properties of titanates from the dynamometer test results. And we introduced the thrust test machine to evaluate friction materials easily[2]. In this study, we have improved the thrust test condition to the repetition of sliding and stopping instead of the continuous sliding. In this interval method, we have controlled the temperature of the friction surface, and have been able to observe a phenomenon of wear that occurs under high temperature in our laboratory. Then we clarified the correlation between powder characteristics and brake performances.

There are various requirements, such as NVH performance, wear resistance, stability in friction level, rotor compatibility, etc. for brake pad of friction materials. In our previous report, we reported that platelet titanium compounds stabilize the friction value and change the effectiveness depending on the difference in the chemical formulation. In this report, we synthesized two kinds of platelet titanate compounds and made the brake pads mixed with both materials in a particular ratio. The brake effectiveness performance tests and the wear performance tests have been conducted in accordance with JASO C-406 and JASO C-427. As a result, when two kinds of titanate compounds with different rotor attacks were mixed, they indicated the wear characteristics that wouldn't result in separate respective use; only when mixed together.

There are various requirements, such as NVH performance, wear resistance, stability in friction level, rotor compatibility, etc. for friction materials of brake pads. In these materials, potassium titanate fiber is widely used due to its specific benefits that contribute to stability in friction level and low wear. Focusing on titanate compounds including potassium titanate fiber, we have proceeded with an analysis of the relationship between their powder properties and brake performance. Before the evaluation, various types of titanate compounds were prepared for comparison, according to their chemical composition, size and crystal structure. We measured the powder properties by a powder tester. The brake performance tests have been conducted with NAO formulations in accordance with JASO C-406 P1 category. The test results showed some specific benefits for brake performance in the formulation with TERRACESS added.