Development of Iron Based Brake Friction Material by Hot Powder Preform Forging Technique used for Medium to Heavy Duty Applications

Abstract

A promising friction material, Iron -based friction material, was prepared by powder metallurgy (PM) processing utilizing hot powder preform forging (near net-shape).The preparation of the product and its characterization are presented in this paper. These products are useful in heavy duty Military Aircraft applications such as AN-32. In order to eliminate costly environmental control systems to protect products during their high temperature processing (as is conventionally practiced employing hydrogen gas), the present investigation relies on carbon (mixed in the brake pad formulation) as reducing agent and high temperature oxidation resistant glassy coating (separately developed) applied over the product's surface after cold compacting. After conducting an initial characterization such as hardness, density and Pin-on Disc tests, the samples were tested in sub-scale dynamometer under Rejected Take Off conditions. It was observed that the obtained density in the present investigation is higher than the reported density obtained by sintering route, and wear is on the lower side of the range as per the Aeronautical Standards. Optical metallography was used to investigate the microstructure of friction, interface and backing layer. It was observed that the distribution of ingredients in matrix was homogeneous. The results also indicate that the coefficient of friction is more stable, and wear is lower with respect to temperature rise. .

Effects of solid lubricants, load, and sliding speed on the tribological behavior of silica reinforced composites using design of experiments

“…The essential requirements are high wear resistance, high friction, superior thermal stability and conductivity, low heat expansion coefficient, high stiffness, high fracture toughness and high strength [1,2,3,4]. Some of these properties are contradictory, and usually do not coexist in a homogenous material, for example, the wear resistance and the friction coefficient, and the strength and the toughness.…”

Conventional and unconventional materials used in the production of brake pads – review

“…This stems from the fact that powder metallurgy technology requires the use of solid lubricants, which later serve as lubrication of the brake pad-brake disc meeting point. Appropriate manufacture technology, taking into account forging and annealing the pad, instead of the regular pressure sintering, improves the mechanical properties of the final product (also ensuring increased hardness) [202,203]. Unfortunately, high steel fraction in the pad leads to the formation of deep scratches in the disc, which is not desired.…”

“…This phenomenon, however, has its benefits. It makes the connection between the fraction material and the backing plate easier, greatly facilitating the production process [202]. The properties of steel described above make brake pads with high steel content serve well in brake systems in airplanes and in any other application requiring high and stable coefficient of fraction for the price of a significant wear ratio [204].…”

High-Speed Tribological and Mechanical Properties of Layered Fe/SiC Composites

“…However, the high fabrication cost, complex fabrication methods, poor oxidation resistance at high temperatures, and poor interlaminar properties restricted their use to specialized applications ( Ref 2). Fe/SiC MMCs have been found to be an alternative inexpensive choice and have been studied at both low (Ref [3][4][5][6][7][8] and high-braking speeds (Ref 9). The MMCs with a uniform distribution of 20 % volume fraction reinforcement of SiC in the Fe matrix were found to possess good tribological properties.…”