Key Engineering Materials Vol. 837

Abstract: To study the reaction threshold and damage characteristic under low amplitude loading, two HMX based explosives were chosen for the study. Low amplitude loading experiment was conducted based on card gap test. By adjusting the thickness of card, the applied pressure on the explosive sample was changed. The reaction situation of the explosive was judged by the witness board and the steel tube. The results show that the explosives, especially the casting molding explosive having the reaction threshold and detonation threshold. The detonation threshold of the casting molding explosive is 4.72~5.28GPa and the reaction threshold is 2.34~2.46GPa. The detonation threshold of the pressed fitting explosive is 2.46~2.72GPa and the reaction threshold is 2.12~2.23GPa.The damage characteristics of samples before and after shock loading were studied by use of CT system. The results of CT show that no macro-damage appear in explosive by pressed fittingaftershock damage, while cavity appear in explosive by casting molding in the position above 7~8mm of the witness board, the cavity’s length is 7~8mm, diameter is 1~2mm.

Abstract: The article concludes the drum index and wear index of sinter ores by times continued drum test. Based on the test results, we analysis the fragmentation situation of sinter ores and the principle which effects the grade distribution under drum test. The results show that after drum test, the quality of sinter ores between 0.00-5.00mm and 10.00-16.00mm rises apparently, while other part all get lower. What`s more, when the times of drum test are same, the powdery degree will get bigger if the time is longer. When the time of drum test is same, the powdery degree will get bigger if the times are more. When the times and times are all the same, the powdery degree will be closely, which shows the results fits the Experimental errors.