Specimens after Test

Cleaning Specimens after Test Before specimens are cleaned, their appearance should be observed and recorded. Locations of deposits, variations in types of deposits, and variations in corrosion produces are extremely important in evaluating localized corrosion such as pitting and concentration-cell attack. 

Figure 5. Bunsen burner burning test of graphite fiber reinforced polyimide composites. Key a, TSTR-XL-PI/GrF specimen before test b, TSTR-XL-PI/GrF specimen after test and c, PMR-15-PI/GrF specimen after test.

Figure 5. Sulfur-sand compression test specimen, after test...

Brittle failure was exhibited by all materials, which indicated that at temperatures down to 76°K the stresses imposed upon these materials by the bending are sufficient to crack them and cause loss of adhesion. The important consideration here, however, is not whether a sealant passes or fails this test, but how it reacts to the stress. The test is most severe and it is doubtful that any existing sealant, without considerable reinforcement, will show enough strength and flexibility to be bent under these conditions and not break. But the mode of failure does suggest that some polymers are not as brittle as others and have promise as a basis for further modifications. Photographs of representative bend specimens, after test, are shown in Fig. 2. 

Fig. 2, Representative bend specimens after testing at 76°K (a) butyl formal, butyl ether, and polysulfide blend (b) fluorosilicone (c) polysulfide (d) silicone (e) polyurethane (f) epoxy (g) epoxy-silicone and (h) carboxyl terminated polybutadiene and epoxy blend. 

Fig. 3. Representative reinforced bend specimens after testing at 76 K (a) glass-fabric-reinforced amorphous silicone and (b) glass-fabric-reinforced Adiprene L-100.

Figure 7 Left sandstone-specimen after storage, before testing right limestone-specimen after testing...

CFR 40.99 — How long does the laboratory retain specimens after testing ... 

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