Fully Characterizing Brake Pad Materials to Improve Performance and Lower Development Costs
Combining benchtop mechanical testing of smaller brake material samples with rapid 3D surface metrology makes it possible to analyze results more quickly than ever before.
Researching how different materials influence brake pad performance and durability involves a vast amount of back-and-forth testing and metrology analysis. Brake materials that seem to be good candidates for improved braking or that can meet ever more stringent environmental regulations are typically evaluated first by metrology analysis, then by dynamometer tests, which simulate the real-world conditions necessary to stop a vehicle. Materials that pass these steps then go through extensive on-vehicle stopping tests that require the brake pads and rotors are in their final form. Clearly this is a very necessary but complex and cost-intensive process for brake manufacturers. Anything that can help streamline these requirements is of intense interest to the industry. This article discusses how combining benchtop mechanical testing of smaller brake material samples with rapid 3D surface metrology makes it possible to perform many of the pre- and post-test analyses more quickly and cost-effectively than ever before.
Development of new materials for automotive brake applications comes with many challenges, including formulation of materials that meet expected (usually more demanding) performance; that enable reduction in manufacturing cost; and that provide compliance with any new safety and environmental regulations. Brake materials are typically evaluated prior to on-vehicle stopping tests by a full-scale dynamometer. Dynamometers allow testing of the real pads and/or rotors under protocols simulating the conditions necessary to stop a vehicle. Different standards have long been in prevalent use by this specialized industry, such as the SAE J2522 developed by the AK Working Group, which represents European manufacturers of passenger car brakes. This test was developed to evaluate the effectiveness of the brake pad and the rotor system under varying conditions of pressure, temperature, speed, and deceleration.