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原文传递 Fracture Growth Testing of Titanium 6AL-4V in AF-M315E.

题名：	Fracture Growth Testing of Titanium 6AL-4V in AF-M315E.
作者：	Sampson, J. W.; Martinez, J.; McLean, C.
关键词：	Fracturing, Crack propagation, Load tests, Weld tests, Titanium alloys, Failure, Failure analysis, Exposure, Stress intensity factors, Yield point, Propellants, Monopropellants, Ammonium compounds, Fuel tanks, Crack tips, Surface cracks, Defects, Tensile strength, Microhardness
摘要：	The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant in orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent flaws will not cause failure during the design life. Material property inputs for this analysis require testing to determine the stress intensity factor for environmentally-assisted cracking (K (sub EAC)) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched specimens SE(B) representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to the monopropellant at 50 degrees Centigrade for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor of the Ti 6Al-4V forged tank material when exposed to AF-M315E monopropellant was found to be at least 22.0 kilopounds per square inch. The stress intensity factor of the weld material was at least 31.3 kilopounds per square inch.
总页数：	Sampson, J. W.; Martinez, J.; McLean, C.
报告类型：	科技报告