1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
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4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR4777BAEROSPACEINFORMATION REPORT AIR4777 REV. BIssued 1994-09 Reaffirmed 2012-05
5、Revised 2013-12 Superseding AIR4777A Nondestructive Inspection (NDI) Methods Used During Production and Operation of Aircraft Wheels and Brakes RATIONALEAIR4777B is the result of a Five Year Review and subsequent update of this document. 1. SCOPE This SAE Aerospace Information Report (AIR) identifie
6、s current nondestructive inspection (NDI) methods used to ensure product integrity and maximize “in service“ life of the major structural components of aircraft wheel and brake assemblies. 2. APPLICABLE DOCUMENTS The following publications form a part of this document to the extent specified herein.
7、 The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in
8、 this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sa
9、e.org.AMS2300 Steel Cleanliness, Premium Aircraft-Quality, Magnetic Particle Inspection Procedure AMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection Procedure AMS2442 Magnetic Particle Acceptance Criteria for Parts AMS2630 Inspection, Ultrasonic Product Over 0.5 inch (12.7 mm)
10、 Thick AMS2641 Vehicle, Magnetic Particle Inspection Petroleum Base AMS2644 Inspection Material, Penetrant SAE INTERNATIONAL AIR4777B Page 2 of 9 AMS2658 Hardness and Conductivity Inspection of Wrought Aluminum Alloy Parts AMS3044 Magnetic Particles, Fluorescent, Wet Method, Dry Powder AMS3045 Magne
11、tic Particles, Fluorescent, Wet Method, Oil Vehicle, Ready-to-Use AMS-STD-2154 Inspection, Ultrasonic, Wrought Metals, Process For AS3071 Acceptance Criteria - Magnetic Particle, Fluorescent Penetrant, and Contrast Dye Penetrant Inspection 2.2 ASTM Publications Available from ASTM International, 100
12、 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM B594 Standard Practice for Ultrasonic Inspection of Aluminum-Alloy Wrought Products for Aerospace ApplicationsASTM E10 Standard Test Method for Brinell Hardness of Metallic Materials ASTM E18 St
13、andard Test Methods for Rockwell Hardness of Metallic Materials ASTM E384 Standard Test Method for Knoop and Vickers Hardness of Materials ASTM E709 Standard Guide for Magnetic Particle Testing ASTM E1004 Standard Test Method for Determining Electrical Conductivity Using the Electromagnetic (Eddy Cu
14、rrent) MethodASTM E1220 Standard Practice for Visible Penetrant Testing Using Solvent-Removable Process ASTM E1417 Standard Practice for Liquid Penetrant Testing ASTM E1444 Standard Practice for Magnetic Particle Testing ASTM E2375 Standard Practice for Ultrasonic Testing of Wrought Products 2.3 U.S
15、. Government Publications Available from DLA Document Services, Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6396, http:/quicksearch.dla.mil/.MIL-HDBK-728/2 Eddy Current Testing MIL-HDBK-728/3 Liquid Penetrant Testing MIL-HDBK-728/4A Magnetic Particle Testing MIL-HDBK-
16、728/6 Ultrasonic Testing MIL-HDBK-6870 Nondestructive Inspection Program Requirements for Aircraft and Missile Materials and Parts MIL-STD-1537 Electrical Conductivity Test for Verification of Heat Treatment of Aluminum Alloys, Eddy Current MethodSAE INTERNATIONAL AIR4777B Page 3 of 9 3. CURRENT NDI
17、 METHODS Today there are five NDI techniques that are commonly used to detect flaws during manufacturing and “in service“ maintenance and overhaul of aircraft wheel and brake structural components. Following is a brief description of each of these methods. A list of associated industry specification
18、s for each inspection method is provided in Table 1. TABLE 1 - NONDESTRUCTIVE INSPECTION INDUSTRY SPECIFICATIONS Specification Title GeneralMIL-HDBK-6870 Nondestructive Inspection Program Requirements for Aircraft and Missile Materials and Parts AMS2658 Hardness and Conductivity Inspection of Wrough
19、t Aluminum Alloy Parts AS3071 Acceptance Criteria - Magnetic Particle, Fluorescent Penetrant, and Contrast Dye Penetrant InspectionLiquid PenetrantMIL-HDBK-728/3 Liquid Penetrant Testing ASTM E1220 Standard Practice for Visible Penetrant Testing Using Solvent-Removable Process ASTM E1417 Standard Pr
20、actice for Liquid Penetrant Testing AMS2644 Inspection Material, Penetrant Magnetic ParticleMIL-HDBK-728/4A Magnetic Particle Testing ASTM E709 Standard Guide for Magnetic Particle Testing ASTM E1444 Standard Practice for Magnetic Particle Testing AMS2300 Steel Cleanliness, Premium Aircraft-Quality,
21、 Magnetic Particle Inspection Procedure AMS2301 Steel Cleanliness, Aircraft Quality, Magnetic Particle Inspection Procedure AMS2442 Magnetic Particle Acceptance Criteria for Parts AMS2641 Vehicle, Magnetic Particle Inspection Petroleum Base AMS3044 Magnetic Particles, Fluorescent, Wet Method, Dry Po
22、wder AMS3045 Magnetic Particles, Fluorescent, Wet Method, Oil Vehicle, Ready-to-Use Eddy CurrentMIL-HDBK-728/2 Eddy Current Testing MIL-STD-1537 Electrical Conductivity Test for Verification of Heat Treatment of Aluminum Alloys, Eddy Current Method ASTM E1004 Standard Test Method for Determining Ele
23、ctrical Conductivity Using the Electromagnetic (Eddy Current) Method UltrasonicMIL-HDBK-728/6 Ultrasonic Testing ASTM B594 Standard Practice for Ultrasonic Inspection of Aluminum-Alloy Wrought Products for Aerospace ApplicationsASTM E2375 Standard Practice for Ultrasonic Testing of Wrought Products
24、AMS2630 Inspection, Ultrasonic Product Over 0.5 inch (12.7 mm) Thick AMS-STD-2154 Inspection, Ultrasonic, Wrought Metals, Process For IndentationASTM E10 Standard Test Method for Brinell Hardness of Metallic Materials ASTM E18 Standard Test Methods for Rockwell Hardness of Metallic Materials ASTM E3
25、84 Standard Test Method for Knoop and Vickers Hardness of Materials SAE INTERNATIONAL AIR4777B Page 4 of 9 3.1 Liquid Penetrant Inspection Liquid penetrant inspection is a nondestructive method of revealing discontinuities that are open to the surfaces of solid and essentially nonporous materials. I
26、ndication of a wide spectrum of flaw sizes can be found regardless of the configuration of the workpiece and regardless of the flaw orientation. Liquid penetrants are drawn into various types of minute surface openings by capillary action. This process is well suited to the detection of many surface
27、 breaking flaws such as cracks, laps, porosity, shrinkage areas, laminations, and similar discontinuities. It is extensively used for the inspection of wrought and cast products of both ferrous and nonferrous metals. In practice, the liquid penetrant process is relatively simple to use and control.
28、The equipment used in liquid penetrant inspection can vary from an arrangement of simple tanks containing penetrant, emulsifier, and developer to sophisticated computer-controlled automated processing and inspection systems. Optimum end results require that the surfaces of parts subjected to liquid
29、penetrant examination be adequately cleaned and free of contaminants that may prevent the penetrant from being drawn into surface breaking flaws. NOTE: Due to the service environment of aircraft wheels and brakes, extensive cleaning is required to ensure reliable liquid penetrant inspection. Cleanin
30、g procedures which outline the most effective methods and products available are contained in the wheel and brake component maintenance manuals. Particular caution should be exercised against over washing during the penetrant removal process and the very undesirable potential of smearing metal over
31、cracks during paint removal or repair operations. The major limitation of liquid penetrant inspection is that it can detect only imperfections that are open to the surface. Other methods must be used for detecting subsurface flaws. Factors that can limit the use of liquid penetrants are significant
32、surface roughness or porosity. Such surfaces produce excessive background signals which interfere with inspection. For example, anodized surfaces can generate a significant amount of background noise and potentially mask small indications. 3.2 Magnetic Particle Inspection Magnetic particle inspectio
33、n is a method of locating surface and subsurface discontinuities in ferromagnetic materials. When the material or part under test is magnetized, magnetic discontinuities that lie in a direction generally transverse to the direction of the magnetic field will cause a leakage field to be formed at and
34、 above the surface of the part. The presence of this leakage field and, therefore, the presence of the discontinuity, is detected by the use of finely divided ferromagnetic particles applied over the surface, with some of the particles being gathered and held by the leakage field. This magnetically
35、held collection of particles forms an outline of the discontinuity and generally indicates its location, size,shape, and depth. The magnetic particle method is a sensitive means of locating small and shallow surface cracks in ferromagnetic materials. Discontinuities that do not actually break throug
36、h the surface are also indicated in many cases by this method, although certain limitations must be recognized and understood. If a discontinuity is fine, sharp, and close to the surface, such as a long stringer of nonmetallic inclusions, a clear indication can be produced. If the discontinuity lies
37、 deeper, the indication will be less distinct. The deeper the discontinuity lies below the surface, the larger it must be to yield a discernible indication. Magnetic particle indications are produced directly on the surface of the part and constitute magnetic pictures of actual discontinuities. Skil
38、led operators can sometimes make a reasonable estimate of crack depth with suitable powders and proper technique. Occasional monitoring of field intensity in the part is needed to ensure adequate field strength. There is little or no limitation on the size or shape of the part being inspected. The s
39、urfaces of parts subjected to magnetic particle inspection must be adequately cleaned to ensure that the particles are sufficiently mobile to accumulate at magnetic field leakage sites and not form false indications. SAE INTERNATIONAL AIR4777B Page 5 of 9 There are certain limitations to magnetic pa
40、rticle inspection. For example: a. Thin coatings of paint and other nonmagnetic coverings, such as plating, may adversely affect the sensitivity of magnetic particle inspection. b. The method can be used only on ferromagnetic materials. c. For best results, the magnetic field must be in a direction
41、that will intercept the principal plane of the discontinuity; thissometimes requires two or more sequential inspections with different magnetizations. d. Demagnetization following inspection is often necessary. e. Post-cleaning to remove remnants of the magnetic particles clinging to the surface may
42、 sometimes be required after testing and demagnetization. f. Exceedingly large currents are sometimes needed for very large parts. g. Care is necessary to avoid local heating and burning of finished parts or surfaces at the points of electrical contact. h. Although magnetic particle indications are
43、easily seen, experience and skill are sometimes needed to judge their significance.3.3 Eddy Current Inspection Eddy current inspection is based on the principles of electromagnetic induction and is used to identify or differentiate among a wide variety of physical, structural, and metallurgical cond
44、itions in electrically conductive ferromagnetic and nonferromagnetic metals and metal parts. Eddy current inspection can be used to: a. Measure or identify such conditions and properties as electrical conductivity, magnetic permeability, grain size, heat treatment condition, hardness, and physical d
45、imensions. b. Detect seams, laps, cracks, voids, and inclusions. c. Sort dissimilar metals and detect differences in their composition, microstructure, and other properties. d. Measure the thickness of a nonconductive coating on a conductive metal, or the thickness of a nonmagnetic metal coating on
46、a magnetic metal. Because eddy currents are created using an electromagnetic induction technique, the inspection method does not require direct electrical contact with the part being inspected. The eddy current method is adaptable to high-speed inspection and, because it is absolutely nondestructive
47、, can be used to inspect an entire production output if desired. The method is based on indirect measurement, and the correlation between the instrument readings and the structural characteristics and serviceability of the parts being inspected must be carefully and repeatedly established. Eddy curr
48、ent inspection is extremely versatile, which is both an advantage and a disadvantage. The advantage is that the method can be applied to many inspection problems provided the physical requirements of the material are compatible with the inspection method. In many applications, however, the sensitivi
49、ty of the method to the many properties and characteristics inherent within a material can be a disadvantage; some variables in a material that are not important in terms of material or part serviceability may cause instrument signals that mask critical variables or are mistakenly interpreted to be caused by critical variables. Each eddy current inspection must seek to control all the variables except those which the inspection is intended to
