高温下DD6单晶气冷叶片模拟试样拉伸性能试验

通过选晶法制备DD6单晶薄壁圆管模拟试样,对850℃和980℃两种温度下001]晶体取向含与不含气膜孔的薄壁试管进行拉伸性能试验研究.结果表明:在850℃条件下,001]取向含气膜孔的拉伸性能比001]取向不含气膜孔的拉伸性能降低10.5%;在980℃条件下,001]取向含气膜孔的拉伸性能与001]取向不含气膜孔的拉伸性能水平相当,这表明温度越高,气膜孔对薄壁件拉伸性能的影响越不显著;但在980℃ 条件下,001]取向通气状态的拉伸强度比不通气状态下的拉伸强度提高16%.同时,发现圆管表面状态及通气状态是影响单晶薄壁试样高温性能的重要因素,特别是通气状态的存在显著提高了其高温力学性能.

Experimental investigation on tension behavior of DD6 single crystal thin-walled cylindrical specimen under high temperature

The thin-walled simulative specimens of DD6 single crystal superalloy were prepared with selected-crystal method.The tensile properties of thin-walled tube with crystallographic orientations were investigated at 850 ℃ and 980 ℃,and one half of the specimens were plates with film cooling holes.The results show that the orientation tensile properties with film cooling holes are reduced by 10.5% than without film cooling holes at 850 ℃,and the orientation tensile properties with film cooling holes correspond with those without film cooling holes at 980 ℃.It indicates that when the temperature is higher,the effect to tensile properties is more significant.However,the orientation tensile properties with airing condition are increased by 16% than those without airing condition at 980 ℃.Therefore,the surface state and airing condition play a main role to affect the properties of single crystal thin-walled tube.Especially,it is the airing condition that the mechanical properties have obviously improved.