Figure 13. Scanning Electron Microscopy Illustrates EMP Damage Mechanism for Silver/Glass Elastomers
图13：铜/玻璃弹性体电磁脉冲损坏机理的扫描电子显微术图。
Figure 14. Effects of Vibration on Shielding Effectiveness of Conductive Elastomer Gaskets
图14：振动对导电弹性体垫片屏蔽效率的影响。
Heat Aging
热时效
The primary aging mechanism which affects electrical stability of conductive elastomers is the oxidation of filler particles. For materials based on pure silver fillers, particle oxidation is not generally a problem because the oxide of silver is relatively soft and reasonably conductive. If the filler particles are non-noble (such as copper, nickel, aluminum, etc.) they will oxidize readily over time and become nonconductive. Even silver-plated base metal powders, such as silver-plated-copper or silver-plated-aluminum will become non-conductive over time if the plating is not done properly (or if other processing variables are not properly controlled). These are generally batch control problems, with each batch being potentially good or bad.
对导电弹性体的电气稳定性影响最大的老化机理是填充颗粒的氧化。对于基于纯银填充剂的材料，由于银的氧化物相对较软且较导电，因此其颗粒氧化通常不是问题。如果通常颗粒非贵金属（如铜、镍、铝等），它们将会随着时间推移很容易发生氧化，且变为不导电。即使镀银的基底金属粉末，如镀银铜或镀银铝，如果电镀不佳的话，也会随着时间的推移而变为不导电（或者如果其他加工变量没有控制好）。这些通常是批量控制问题，每批可能好或不好。
The most reliable method of predicting whether a batch will be electrically stable is to promote the rate at which poorly plated or processed particles will oxidize, by heat aging in an air circulating oven. For qualification, 1000 hours (42 days) at maximum rated use temperature (with the gasket sample deflected 7-10% between flanges) is the recommended heat aging test for accelerating the effects of long-term aging at normal ambient temperatures. A quicker heat aging test, which correlates well with the 1000 hour test and is useful for QC acceptance testing, involves a 48 hour/150°C oven bake with the gasket sample on an open wire-grid tray (rather than being clamped between flanges). Figure 15 shows typical data for volume resistivity versus time for each of these tests.
预知某一批是否电气稳定的最可靠的方法是：通过在空气循环烘箱内进行热老化，提高电镀不佳或加工不佳颗粒的氧化速度。鉴定时，为了使正常环境温度下长期的老化效果加速，所建议采用的热老化试验为：在最高额定使用温度下放置1000小时（42天）（法兰之间的垫片试样变形达7-10%）。和1000小时试验十分相关，且可用于质量控制验收试验的较快热老化试验，涉及到将垫片试样放置在开式线栅托盘上（而不是夹在法兰之间），在烘箱内150°C烘烤48小时。图15给出了每个这种试验中体积电阻系数与时间函数关系的典型数据。
华译网上海翻译公司曾经翻译过大量有关铜/玻璃弹性体资料文件，Beijing Chinese Subtitling Translation Service Agency has translated many technical documents about Silver/Glass Elastomers.
Figure 15. Typical heat aging characteristics of XXXX plated-powder-filled conductive elastomers. Flanged 1000-hr test recommended for qualification. Unflanged 48-hr. test recommended for QC acceptance.
图15：XXXX 电镀粉末填充的导电弹性体的典型热老化特性。鉴定时建议采用法兰连接1000小时试验。质量控制验收时建议采用非法兰连接的48小时试验。
Note: It is essential that no source of free sulfur be placed in the aging oven, as it will cause the material to degrade electrically and mask any oxidation aging tendencies. Common sources of sulfur are neoprenes, most cardboards and other paper products.
注意：必须注意在老化烘箱内不得放置有游离硫的源，这是因为它会导致材料电气损失并掩盖氧化老化趋势。硫的常见源是氯丁橡胶、大多数纸板和其他纸制品。
Outgassing
释气
Many spacecraft specifications require that nonmetallic components be virtually free of volatile residues which might outgas in the hard vacuum environment of space. The standard test method for determining outgassing behavior is ASTM E595-93, which provides for measurement of total mass loss (TML) and collected volatile condensable materials (CVCM) in a vacuum environment. Data for a number of XXXX conductive elastomers, based on ASTM E595-93 testing done by NASA Goddard Spaceflight Center, is presented in Table 20. The normal specification limits or guide-lines on outgassing for NASA applications are 1% TML max., and 0.1% CVCM max.
许多太空船规范都要求非金属部件应几乎不含挥发性残渣，它会在太空高真空环境中释气。确定释气特性的标准试验方法是ASTM E595-93，它可在真空环境中测量总的质量损失，并收集CVCM。表20中给出了许多XXXX 导电弹性体的数据，这些都是由NASA 戈达德航天中心基于ASTM E595-93所试验得出的。NASA应用系统中有关释气的正常规范限值或准则为最大1%总质量损失，和最大0.1％CVCM。
Table 20: Outgassing Data for Conductive Elastomers
表20：导电弹性体的释气数据
Outgassing Data for Conductive Elastomers (Per ASTM E595-93)
导电弹性体的释气数据（根据ASTM E595-93）
Special Post Curing
特殊二次硬化 TML % Limit <1.0%
TML % 限值 <1.0% CVCM% Limit <0.1%
CVCM% 限值<0.1% NASA GSFC Data Reference
NASA戈达德航天中心参考数据
CHO-SEAL 1212 None 无 0.40 0.13 15140
CHO-SEAL 1215 None 无 0.45 0.10 15142
CHO-SEAL 1217 None 无 0.45 0.01 15231
CHO-SEAL 1221 None 无 0.35 0.02 15249
CHO-SEAL 1224 None 无 0.41 0.10 15211
CHO-SEAL 1285 None 无 0.62 0.09 15251
CHO-SEAL 1287 None 无 0.63 0.03 15165
CHO-SEAL 1298 None 无 0.12 0.02 28381
CHO-SEAL 1501 None 无 0.50 0.10 15247
CHO-SEAL S6305 Yes 是 0.15 0.09 23961
CHO-SEAL 6370 Yes 是 0.19 0.10 23964
CHO-SIL 1401 None 无 0.92 0.37 15213 |
