Electromagnetic Shielding and Corrosion Protection for Aerospace Vehicles

0387460942......Page 1
Electromagnetic Shielding
and Corrosion Protection for
Aerospace Vehicles......Page 2
Copyright Page......Page 3
Table of Contents......Page 4
Preface......Page 8
Acknowledgment......Page 10
1.2 Importance of Electromagnetic Shielding and Corrosion Prevention for Aircraft......Page 11
2.1 Corrosion......Page 14
2.2.1 Electrochemical Aspects......Page 15
2.2.2 Environmental Aspects......Page 17
2.2.3 Metallurgical Aspects......Page 19
2.3.1 Uniform Attack......Page 20
2.3.3 Crevice Corrosion......Page 21
2.3.4 Pitting......Page 22
2.3.8 Stress Corrosion......Page 23
3.2 Factors that Determine Shielding Effectiveness......Page 25
3.3.1 Absorption Loss......Page 26
3.3.2 Reflection Loss......Page 28
3.3.4 Effect of Near-Field Sources on Shielding Effectiveness......Page 29
3.4 Practical Electromagnetic Shielding......Page 30
3.5 Role of Conductive Sealants in Electromagnetic Shielding......Page 32
4.2 Stainless Steel Test Joint for DC Resistance and Shielding Effectiveness Measurements......Page 33
4.3 DC Resistance Measurements......Page 36
4.4 Shielding Effectiveness Measurements......Page 37
4.5 Measurement Results on the Relationship Between DC Resistance and Shielding Effectiveness......Page 38
4.6 Effect of Plate Separation on Shielding Effectiveness......Page 41
5.1 Identification of Materials......Page 43
5.2.1 Aluminum Test Joints......Page 46
5.2.2 Measurement Results of DC Resistance Versus Salt Spray Exposure......Page 50
5.2.3 Measurement Results of Shielding Effectiveness Versus Salt Spray Exposure......Page 51
5.4.1 Evaluation of Laboratory Sealant Test Samples......Page 54
6.1 Introduction......Page 64
6.1.2 Visits to Air Force Installations......Page 65
6.2.2 Field Test Methods......Page 70
6.2.3 E-3A Aircraft Field Test Results......Page 79
6.3 Conclusions......Page 80
6.4 Recommendations......Page 81
7.1 Background......Page 82
7.2 Basis/Rational Behind the 2.5-Milliohm Bonding Requirements......Page 83
7.4 Proposed Changes to Standards, Specification and Handbooks......Page 85
7.4.1 Modifications to MIL-B-5087B......Page 87
7.4.2 Modifications to MIL-STD-188-124A......Page 89
7.4.3 Modifications to MIL-STD-1541......Page 92
7.4.4 Modifications to MIL-STD-1542......Page 93
7.4.5 Modifications to MIL-STD-454K......Page 94
7.4.6 Modifications to MIL-HDBK-253......Page 95
7.4.7 Modifications to AFSC Design Handbook 1-4......Page 98
7.4.8 Modifications to NATO STANAG No. 3659......Page 104
7.6.2. Annodized and Chemical Conversion Type Treated Aluminum Surfaces......Page 106
7.7.1 Resealable Joints in Salt Spray Chamber......Page 107
7.8 Shielding Effectiveness of Non-Conductive Corrosion Inhibitive Sealant......Page 108
7.9 Aerospace Material Specification......Page 109
8.2 Stamped and Formed Metal Gaskets......Page 110
8.3 Wire Mesh Gaskets......Page 111
8.5 Conductive Fabric-Clad Foam Gaskets......Page 112
8.6 Conductive Gel Gaskets......Page 113
Appendix A: Shielding Effectiveness Data for Test Joints with Varying Resistances......Page 114
Appendix B: Shielding Effectiveness Versus Plate Separation Data......Page 123
References......Page 128
Index......Page 129