【摘要】 采用紧凑拉伸 (CT)试样 ,研究了含氢 110 μg/ g的 Ti- 2 Al- 2 .5 Zr钛合金在室温的静载延迟裂纹扩展 (da/ dt)和疲劳加载裂纹扩展 (da/ d N )行为 ,用扫描电镜观察了断口形貌。结果表明 ,Ti- 2 Al- 2 .5 Zr合金含氢 110μg/ g即足以引起材料的静载氢致延迟断裂 ,氢在裂纹尖端扩散聚集并析出氢化物 ,导致材料变脆 ,是氢致延迟断裂的微观机制 ;而相同含氢量时对疲劳断裂过程的影响微弱 ,疲劳断裂受通常的裂纹萌生、稳态扩展和瞬断机制控制。更多还原

【Abstract】 The compact tension(CT) samples of Ti-2Al-2.5Zr titanium alloy bearing 110μg/g hydrogen were employed to study behaviors of sustain load cracking(SLC) and fatigue cracking. Fracture surfaces were observed by SEM. Results show that this alloy containing 110μg/g hydrogen is easily subject to delayed hydrogen cracking(DHC), which owes to hydrogen diffusing to the crack tip accumulating, leading to hydrides precipitating and separating from substrate. But for fatigue loading, the same content hydrogen has little effects on cracking, which is controlled by the normal fatigue fracture mechanism of crack initiation, stable propagation and sudden rupture process.更多还原