A method to monitor non-ferrous debris in ferrographic analysis

Abstract

Non-ferrous debris in oil sample provide important information about the wear condition of a wear couple containing non-ferrous metal components. In order to collect wear debris of non-ferrous metal material more effectively and deposit them on a ferrogram in a stable depositing ratio, the method of employing magnetic fluid as a magnetization agent to collect non-ferrous wear debris in ferrography was attempted. Magnetic fluid constituting Fe 3 O 4 magnetic particles was prepared using a precipitation reaction. Tetrachloroethylene was used as a carrier liquid to ensure that magnetic fluid can be easily mixed with lubricant oil sample. Oleic acid was used as a surfactant, which enables magnetic particles to adhere to the surface of non-ferrous wear debris. Then the non-ferrous wear debris was magnetized and deposited on a ferrogram in a stable depositing ratio. Copper debris was chosen as an example of non-ferrous debris to illustrate the magnetization effect of the magnetic fluid. With the help of magnetic fluid, the ferrographic analyst will achieve the operating condition of the machine more accurately.

Qualitative ferrographic analysis method by quantitative parameters of wear debris characteristics

“…This group of wear debris is unique, having characteristics which bear evidence of the tribological conditions under which it was generated, or in other words, the operating condition of the wear system can be only determined by the characteristics of this group of wear debris. That is the main idea of the theory of debris group (Liu et al, 2010). The debris group refers to a group of wear particles organized after a certain pattern, which includes both the way of how the wear particles are produced in wear system and the way of how the wear particles are deposited by ferrograph.…”

“…This group of wear debris is unique, having characteristics which bear evidence of the tribological conditions under which it was generated, or in other words, the operating condition of the wear system can be only determined by the characteristics of this group of wear debris. That is the main idea of the theory of debris group (Liu et al , 2010).…”

“…Ferrography is a technique for the collection and determination of the concentration and morphology of wear particles suspended in lubricants (Roylance, 2005;Liu et al, 2010). The goals of the ferrographic analysis are to diagnose the current condition of machines and to be able to predict any future problems (Yardley, 1979;Akagaki and Kato, 1992;Prabhakaran and Jagga, 1999;Macian et al, 2006).…”

“…During the operation of the machinery, wear occurs whenever there is interaction between moving surfaces, which causes the formation of wear particles from the moving parts resulting in their continual degradation. Ferrography is a technique for the collection and determination of the concentration and morphology of wear particles suspended in lubricants (Roylance, 2005; Liu et al , 2010). The goals of the ferrographic analysis are to diagnose the current condition of machines and to be able to predict any future problems (Yardley, 1979; Akagaki and Kato, 1992; Prabhakaran and Jagga, 1999; Macian et al , 2006).…”

Magnetization mechanism of nonferrous wear debris by magnetic fluid in ferrography

“…12,13 The same technology has been applied in the experiments for the separation of UHMWPE wear debris generated in hip simulators, from bovine serum lubricating fluid. 14 We have developed a novel method of separating or precipitating the nonferrous debris by magnetic means at the Tribology Laboratory of China University of Mining and Technology 15 in which a new kind of magnetic fluid containing magnetite nanoparticles had been employed to effectively magnetize the nonferrous debris. The objective of this work is to discuss the magnetization mechanism of the nonferrous debris in detail through experimental analysis and modeling simulation.…”