The impact tests

The mechanical properties of the HDPE/PA12 compatibilized and non-compatibUized UDP, CPC, MRB and NOM composites were studied in a similar way. In order to avoid repetition in this subsection, a direct comparison is given between the respective systems reinforced by either PAG or PA12 to better assess the reinforcing capability of the two 

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Tensile and flexural properties were studied with an Instron 4204 testing machine. Tensile tests were performed on the drawn strands at a test speed of 3 mm/ min, while three-point-bending tests (ISO 178) at a speed of 5 mm/min were applied to the injection molded specimens. Charpy impact strength was measured of the unnotched samples with a Zwick 5102 pendulum-type testing machine using a span of 70 mm. The specimens (4 X 10 X 112 mm) used for three-point-bending tests were also used for the impact tests. It should be noted that neither the tensile tests for the strands nor the impact tests were standard tests. The samples were conditioned for 88 h at 23°C (50% r.h,) before testing. 

Impact tests Such tests reveal the resistance of coatings to deformation and destruction by concentrated sudden stresses. They thus throw considerable light on the integrity of the metal-coating bond. Changes in adhesion through chemical reaction at the paint/metal interface will be reflected in the impact-test values. 

The impact test, with its usual notch, indicates the energy required to break notched specimens under standard conditions. It is calculated as foot-pounds per inch (J/m) of notch and is usually calculated on the basis of 1 in. wide specimen, although the specimen may be thinner in the lateral direction. 

Wenograd, A Photographic Study of The Impact Test , ERDE Rept No 6/12/60, AD 241207... 

Figure 4. Schematic drawing of the impact test facility used by PSRI. (Knowlton, 1996.)...

In contrast to the impact tests, these can be analysed toughness is reported as the critical energy release rate (7, or the stress concentration factor K Values may tange from 5000 J. nr for a tough nylon or polycarbonate down to 350. J/m lor buttle unmodified polystyrene. The values can be sensitive to rale and temprature... 

Weld Impact Test Requirements. Where two base metals having different required impact energy values are joined by welding, the impact test energy requirements shall conform to the requirements of the base... 

The impact testing machine shown in Figure 15.29 measures the arc, or angle, through which the pendulum swings and converts this measurement to the energy needed to break the specimen. This energy is reported in either foot-pounds (fit-lbs) or Newton-meters (N-m.), also called joules. 

The Impact Test, also called Falling Weight Test was devised by W. Will, SS 1, 209(1906) and by H. Kast, SS 4, 263 (1909) and the history of test was reviewed by H. Koenen et al in Explosivstoffe 8, 178(1958). The test differs essentially from the gap test because its pressures (several hundred, or up to several thousand atmospheres) are much lower and its time scale (hundreds of microseconds, depending on the length of the hammer) much longer. In the test conducted at NOL, a 35-mg sample of expl or propint was placed on a... 

J) O.E. Sheffield, "Application of the Impact Test to the Study of Cast and Pressed Explosives , PAMR—24 (1952)... 

According to the tests conducted at PicArsn, aliophany 1 azide is practically non-hygroscopic (gain in wt at 90% RH and RT 0.19% in 24 hrs). The 100° thermal stability test showed that die azide is appreciably unstable on prolonged heating (loss of wt 5.98% in 24 hrs and 7.15% in 48 hrs). The impact test with a 2 kg wt showed that the azide is insensitive. Contact with a hot wire did not cause the material to inflame to a self-propagating reaction (Ref 3i p 35)... 

Tests conducted at Pic Arsn(Ref 4) have shown that a compn consisting of LNAGu 33.6, KClOs 14.3, SbjSj 21.5 and glass 30.6%, loaded wet with 2% of shellac, proved to be suitable for caps in lieu of MF or LA compns. The impact test of the above mixt with a 2 kg wt was 2.5 cm, and the delay assembly of a M-48 fuse contg that mixt gave no failures in 30 tests... 

Amm acetate soln and add sufficient Na bichromate soln to ppt all lead as chromate. Test for the completion of destruction by transferring a portion of slurry to a filter paper and treating the filtrate with a few drops of Na bichromate soln. Confirm the absence of LA by washing.with distd w,the residue on filter,free of so azide salts, drying it,and subjecting a 20 mg portion to the impact test, using 2 kg wt. The material should not detonate... 

Microscopy. Three levels of magnification were required to characterize adequately the morphology of the molded polymer samples and of fracture surfaces after the impact test. A low power binocular microscope covering the magnification range from 2 to 12 times permitted initial evaluation of the fracture surface after which specific areas and... 

Impact and Tensile Testing. A number of mechanical tests were carried out on test bars cut from the molded sheets. For the impact tests six sample bars were cut for each mixing and composition condition while for the tensile tests four test specimens were prepared. The reported results are average values as determined from that number of test bars. The tensile tests were run at a crosshead speed of 0.2 inch/min. Table I lists the results for the impact and tensile tests of the dry blended mate-... 

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