1、Designation: D7898 14Standard Practice forLubrication and Hydraulic Filter Debris Analysis (FDA) forCondition Monitoring of Machinery1This standard is issued under the fixed designation D7898; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe purpose of this practice is to describe best practice methods for the analysis of filter deb
3、ris frommachinery lubrication or hydraulic systems primarily for the purpose of machinery conditionmonitoring. The purpose of Filter Debris Analysis (FDA) is to determine the health of oil-wettedmachinery by analyzing the size, quantity, morphology, and composition of debris trapped by thesystem fil
4、ter. FDA is emerging as an important condition monitoring technique as fine filtrationbecomes more common and the associated reduction of metallic particulates makes traditionalelemental analysis of the lubricant less effective. System filters have an added advantage overtraditional sample-based tec
5、hniques in that they capture a high percentage of the total system debris(metallic, non-metallic, and organic particulate contamination) within the size range useful formachinery condition monitoring.1. Scope1.1 This practice is intended to cover the extraction,analysis, and information management p
6、ertaining to visiblewear debris collected from oil system filters or debris retentionscreens. Further, it is intended that this practice be a practicalreference for those involved in FDA.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in th
7、isstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. R
8、eferenced Documents2.1 ASTM Standards:2D7684 Guide for Microscopic Characterization of Particlesfrom In-Service LubricantsD7685 Practice for In-Line, Full Flow, Inductive Sensor forFerromagnetic and Non-ferromagnetic Wear Debris De-termination and Diagnostics for Aero-Derivative and Air-craft Gas Tu
9、rbine Engine BearingsD7720 Guide for Statistically Evaluating Measurand AlarmLimits when Using Oil Analysis to Monitor Equipmentand Oil for Fitness and ContaminationD7690 Practice for Microscopic Characterization of Par-ticles from In-Service Lubricants by Analytical Ferrogra-phyF316 Test Methods fo
10、r Pore Size Characteristics of Mem-brane Filters by Bubble Point and Mean Flow Pore TestG40 Terminology Relating to Wear and ErosionD4175 Terminology Relating to Petroleum, PetroleumProducts, and Lubricants2.2 Other Standards:TTCP-AER-TP3-TR01-2010 Guide for Filter Debris Analy-sis33. Terminology3.1
11、 Definitions:3.1.1 abrasive wearwear due to hard particles or hardprotuberances forced against and moving along a solid surface.D41753.1.1.1 DiscussionAlso called cutting wear in some in-stances such as machining swarf.1This practice is under the jurisdiction of ASTM Committee D02 on PetroleumProduc
12、ts, Liquid Fuels, and Lubricants and is the direct responsibility of Subcom-mittee D02.96 on In-Service Lubricant Testing and Condition Monitoring Services.Current edition approved Jan. 15, 2014. Published February 2014. DOI:10.1520/D7898-14.2For referenced ASTM standards, visit the ASTM website, ww
13、w.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Published by the Technical Co-operation Program (TTCP), July 2010.Copyright ASTM International, 100 Barr Harbor Drive,
14、 PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.1.2 abrasive wear particleslong wire-like particles inthe form of loops or spirals that are generated due to hard,abrasive particles present between wearing surfaces of unequalhardness; sometimes called cutting wear particles or ribbo
15、ns.D76843.1.1.3 three body abrasive wearform of abrasive wear inwhich wear is produced by loose particles introduced orgenerated between the contacting surfaces. D76843.1.1.4 two body abrasive wearform of abrasive wear inwhich the hard particles or protuberances that produce the wearof one body are
16、fixed on the surface of the opposing body. G403.1.2 adhesive wearwear due to localized bonding be-tween contacting solid surfaces leading to material transferbetween the two surfaces or loss from either surface. G403.1.2.1 DiscussionAlso called sliding wear or rubbingwear.3.1.2.1 rubbing wear partic
17、lesparticles generated as aresult of sliding wear in a machine, sometimes called mildadhesive wear. Rubbing particles are free metal platelets withsmooth surfaces, from approximately 0.5 to 15 m in majordimension and with major dimension-to-thickness ratios fromabout ten to one for larger particles
18、to about three to one forsmaller particles.Any free metal particle 15 m and several times longer thanthey are wide. Some of these particles have surface striations asa result of sliding, and they frequently have straight edges.Their major dimension-to-thickness ratio is approximately tento one. D768
19、43.1.2.1 DiscussionSevere Sliding Particles can be gener-ated as a result of inadequate lubrication, wrong lubricant,extreme loading, or no lubricant. Ferrous particles can oftenexhibit heat tinting coloration on their surface as a result of thehigh frictional temperatures experienced during this pr
20、ocess.3.1.3 asperitya protuberance in the small-scale topo-graphical irregularities of a solid surface. G403.1.4 contaminant particlesparticles introduced from anextraneous source into the lubricant of a machine or engine.D76903.1.5 debrisin tribology, particles that have become de-tached in a wear
21、or erosion process. G403.1.6 debrisin tribology, solid or semi-solid particulatematter introduced to lubricant through contamination or de-tached from a surface due to wear, corrosion, or erosionprocess. D76843.1.7 debrisin internal combustion engines, solid con-taminant materials unintentionally in
22、troduced into the engineor resulting from wear. D41753.1.8 filter debris analysis (FDA)in tribology, a processfor extracting and inspecting debris accumulated on the filtermedia taken from an in-line circulating lubricating system.D76843.1.9 non-ferrous metal particlesfree metal particle com-posed o
23、f any metal except iron.All common nonferrous metalsbehave nonmagnetically except nickel. D76903.1.10 nonmetallic particlesparticles comprised ofcompounds, organic material, glasses, etc. that have boundelectrons in their atomic structure. D76903.1.10.1 nonmetallic amorphous particlesparticles with-
24、out long range atomic order that are transparent and that do notappear bright in polarized light. D76903.1.10.2 nonmetallic crystalline particlesparticles withlong range atomic structure that appear bright in polarizedlight. These may be single crystals but are most likelypolycrystalline or polycrys
25、talline agglomerates. D76903.1.11 rolling contact fatiguedamage process in a tribo-element subjected to repeated rolling contact loads, involvingthe initiation and propagation of fatigue cracks in or under thecontact surface, eventually culminating in surface pits or spalls.G403.1.12 scoringin tribo
26、logy, a consequence of severe slid-ing wear characterized by formation of extensive grooves andscratches in the direction of sliding; also called striation.D76843.1.13 spallingin tribology, the separation of macroscopicparticles from a surface in the form of flakes or chips, usuallyassociated with r
27、olling element bearings and gear teeth, butalso resulting from impact events. G403.1.14 wear particlesparticles generated from a wearingsurface of a machine. D76843.2 Definitions of Terms Specific to This Standard:3.2.1 debrisparticulate recovered from a machine contain-ing both wear-related, benign
28、 (for example, residual overhaulswarf), or organic material, or combinations thereof, foreign tothe system.3.2.2 Ferets diameterthe largest distance between twoparallel lines that just touches the edge of an irregularly shapedparticle. Also known as calliper diameter.3.2.3 ferrous debrismetallic deb
29、ris consisting mainly ofiron (Fe) and exhibiting ferro-magnetic behavior (that is, thematerial is attracted or repelled when exposed to a magneticfield). Recommended abbreviation: Fe.3.2.4 filter bypass systema system by which circulatingfluid can bypass the filter element if the differential pressu
30、reacross the filter becomes excessive due to blockage by con-tamination. Under bypass conditions, fluid can continue tocirculate but will be unfiltered.3.2.5 filter debrisany matter captured in a system filterelement.3.2.6 filter patcha piece of filter material of knownpermeability (mesh opening dim
31、ension) used to capture debrissized greater than the rated mesh opening; usually specified inm. Also known as membrane patch.D7898 1423.2.7 filter patch mesh sizethe diameter of the largestsphere that can pass through the filter patch mesh opening.3.2.8 fine filtrationfiltration applied to a lubrica
32、tion orhydraulic system that meets or exceeds a Beta ratio of 200 for5 m (c) particles (that is, 5(c) 200).3.2.9 graticulefine lines of known spacing used to deter-mine the scaling of microscopic images.3.2.10 metal mapa list of components within a machineby part number or function together with the
33、 components alloyspecification and composition.Also known as materials atlas orcomponent material specification list.3.2.11 parent systemthe mechanical system from whichthe debris sample originated from, for example, helicoptermain rotor gearbox.3.2.12 particle areasthis measurement is used by somea
34、ircraft manufacturers to define the criticality of wear debris. Itis not recommended since it is almost impossible to obtain anaccurate measurement of an individual particle in the fieldwithout using appropriate particle image processing software.3.2.13 particle aspect ratiothe length of a predomina
35、ntlytwo-dimensional particle divided by its width.3.2.14 rolling contact fatigue particlesthese particles aregenerated in a load/unload (cyclic) environment and is a typicalfailure mode for rolling element bearings and gears. Particlesare generated when subsurface cracks, generated by the sig-nifica
36、nt sub-surface shear stress associated with Hertziancontact stresses, propagate to a point where a spall is liberatedfrom the load surface.These particles can be tens of microns upto millimetres in length. Particles may show evidence of themachined load-bearing surface on one face and a roughcrystal
37、line surface (where the crack propagated) on the reverse.Particles may be rolled and reworked by subsequent rollingelements or gear teeth and may then appear as a flattened flakewith characteristic radial cracking from the edges and afissured or crazed edge. Particles are hard and brittle, notdeform
38、able without cracking when load is applied.3.2.15 scale bara reference measurement embedded intoor applied on an image to enable scaling of other objectspresent in that image. The units of measurement must beclearly presented with the scale bar.3.2.16 striationsfine parallel lines or scores on a par
39、ticlesurface.3.2.17 slurrymixture of debris suspended in solvent.3.2.18 wear debris analysisthe analysis of metallic debriswith particular emphasis on size, count, morphology, andcomposition. May also provide some indication of the critical-ity.3.2.19 wear particle atlasa compilation of high resolut
40、ionimages showing the key features of the different types of purewear debris (fatigue, adhesive, and abrasive).4. Summary of Practice4.1 Lubrication and hydraulic system filters are a richsource of information about system health that are seldomexploited for machinery condition monitoring purposes.
41、Thispractice seeks to define some procedures that ensure consistentextraction and analysis of filter debris in order to assess systemhealth.5. Significance of Use5.1 The objective of FDA is to diagnose the operationalcondition of oil-wetted machinery systems in order to identifyabnormal wear or inci
42、pient component failures. Oil systemfilters (typically lubrication system or hydraulic systems)capture the vast majority of metallic and non-metallic debrisgenerated or contained within a system. The exploitation ofthis potential source of information for machinery conditionmonitoring purposes has b
43、een difficult in the past due to theabsence of a clear automated or manual method for extracting,analyzing, reporting, and archiving the debris. This practice isprovided to enable a consistent approach to the analysis ofin-service debris captured in filters and is intended primarilyfor lubrication o
44、r hydraulic systems.5.2 Caution shall be exercised when drawing conclusionsbased on particle quantity, composition, and morphology. Anymaintenance or operational actions shall be carefully consid-ered and take into consideration any extant limits provided bythe manufacturer as well as any historical
45、 information knownabout the subject system.6. Filter Elements6.1 Filter elements may be broadly classified as eitherreusable or disposable. Prior to processing a filter element, itshould be understood whether the element is disposable orreusable so that appropriate processing techniques can beapplie
46、d.6.2 This is to ensure disposable elements are not inadver-tently reused following extraction of debris.6.3 Reusable filter elements are typically made from sin-tered metal or woven metal fiber (mesh), but can also employother media types.6.3.1 If a reusable filter is to be reinstalled into a machi
47、ne,then the filter element should be treated as a serviceable part,and as such the following observed:6.3.1.1 Any process, solvent, etc. used to extract wear debrismust be in accordance with the approved maintenance manual.This will typically include a predefined cleaning and dryingprocedure that mu
48、st be conducted prior to reinstalling theelement. Failure to follow approved procedures could result indegraded filter performance or contamination of the oil systemwith residual cleaning solvent, or both. Some filters mayrequire a bubble point test (for example, Test Methods F316)toconfirm the inte
49、grity prior to reinstallation.6.3.1.2 If the approved maintenance manual does notspecify a suitable method for cleaning the reusable filter thatsufficiently extracts debris for analysis, then the filter elementmanufacturer should be consulted to determine an appropriatemethod. Ultrasonic extraction in particular can cause visuallyundetectable damage to some reusable filter media.6.3.1.3 The number of times a filter can be cleaned andreused should also be determined. Some reusable filter ele-ments will only tolerate a finite number of c
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