7075合金低温冲击过程中的能量分布和示波曲线分析
|
摘要
研究了7075铝合金低温冲击过程中的能量吸收情况,冲击试验温度分别为0、-25、-50、-80、-120℃。试验发现,随着温度降低,7075铝合金的冲击裂纹形成功Ei逐渐增加,冲击裂纹不稳定扩展功Eup逐渐减小,但总功E_(add)(即E_i与E_(up)之和)相对稳定。高冲击载荷下的平均强度功Est是影响7075铝合金低温冲击性能的主要因素,而高冲击载荷下的E_(st)是由极值点前后(-50℃)平均冲击载荷F_(ave)的增加和亚稳扩展位移d_(st)的变化共同决定的。
The energy absorption of the 7075 alloy during low temperature impact was investigated at 0,-25℃,-50℃,-80 ℃,-120 ℃,respectively.It is found that with the decrease of temperature,the impact crack shape energy Eiof the 7075 alloy is gradually increased,while the impact crack instability expansion energy Eupof the 7075 alloy is gradually reduced,however,the total energy Eadd(Eaddis the sum of Eiand Eup)is relatively stable.The average strength energy Estunder high impact load is the main factor on the low temperature impact behavior of 7075 alloy,and the average strength energy Estunder high impact load is determined by the increase of the average impact load Faveand the change of the metastable extended displacement dstjointly.
The energy absorption of the 7075 alloy during low temperature impact was investigated at 0,-25℃,-50℃,-80 ℃,-120 ℃,respectively.It is found that with the decrease of temperature,the impact crack shape energy Eiof the 7075 alloy is gradually increased,while the impact crack instability expansion energy Eupof the 7075 alloy is gradually reduced,however,the total energy Eadd(Eaddis the sum of Eiand Eup)is relatively stable.The average strength energy Estunder high impact load is the main factor on the low temperature impact behavior of 7075 alloy,and the average strength energy Estunder high impact load is determined by the increase of the average impact load Faveand the change of the metastable extended displacement dstjointly.
引文
[1]GUOJIANG D,CHANGCAI Z,YAXIN P,et al.Hot granules medium pressure forming process of AA7075conical parts[J].Chinese Journal of Mechanical Engineering,2015,28(3):580-591.
[2]IBRAHIM M F,SAMUEL E,SAMUEL A M,et al.Impact toughness and fractography of Al-Si-Cu-Mg base alloys[J].Materials&Design,2011,32(7):3 900-3 910.
[3]李向新,陈律,邓岚,等.含Sc航空7075合金的疲劳裂纹萌生及扩展行为[J].金属热处理,2015,40(12):44-48.
[4]曹阳,陈乐平,周全.脉冲磁场对7075合金凝固组织的影响[J].特种铸造及有色合金,2013,33(10):964-968.
[5]MA A,SUZUKI K,NISHIDA Y,et al.Impact toughness of an ultrafine-grained Al-11Si alloy processed by rotary-die equal-channel angular pressing[J].Acta Materialia,2005,53(1):211-220.
[6]MA A,SUZUKI K,SAITO N,et al.Impact toughness of an ingot hypereutectic Al-23Si alloy improved by rotary-die equal-channel angular pressing[J].Materials Science&Engineering,2005,A399(1-2):181-189.
[7]GüR C H,YILDIZ6)I.Non-destructive investigation on the effect of precipitation hardening on impact toughness of 7020Al-Zn-Mg alloy[J].Materials Science and Engineering,2004,A382:395-400.
[8]AL-RUBAIE K S,BARROSO E K L,GODEFROID L B.Fatigue crack growth analysis of pre-strained 7475-T7351aluminum alloy[J].International Journal of Fatigue,2006,28(8):934-942.
[9]唐振廷.GB/T 19748-2005《钢材夏比V型缺口摆锤冲击试验仪器化试验方法》实施指南[M].北京:中国标准出版社,2006.
[10]DIN EN ISO 4287:2010,Geometrical product specifications(GPS)-surface texture:Profile method-terms,definitions and surface exture parameters[P].International Organization for Standardization,Switzerland,2010.
[11]KOBAYASHI T,YAMAMOTO I,NIINOMI M.Introduction of a new dynamic fracture toughness evaluation system[J].Journal of Testing&Evaluation,1993,21,3(3):145-153.
[2]IBRAHIM M F,SAMUEL E,SAMUEL A M,et al.Impact toughness and fractography of Al-Si-Cu-Mg base alloys[J].Materials&Design,2011,32(7):3 900-3 910.
[3]李向新,陈律,邓岚,等.含Sc航空7075合金的疲劳裂纹萌生及扩展行为[J].金属热处理,2015,40(12):44-48.
[4]曹阳,陈乐平,周全.脉冲磁场对7075合金凝固组织的影响[J].特种铸造及有色合金,2013,33(10):964-968.
[5]MA A,SUZUKI K,NISHIDA Y,et al.Impact toughness of an ultrafine-grained Al-11Si alloy processed by rotary-die equal-channel angular pressing[J].Acta Materialia,2005,53(1):211-220.
[6]MA A,SUZUKI K,SAITO N,et al.Impact toughness of an ingot hypereutectic Al-23Si alloy improved by rotary-die equal-channel angular pressing[J].Materials Science&Engineering,2005,A399(1-2):181-189.
[7]GüR C H,YILDIZ6)I.Non-destructive investigation on the effect of precipitation hardening on impact toughness of 7020Al-Zn-Mg alloy[J].Materials Science and Engineering,2004,A382:395-400.
[8]AL-RUBAIE K S,BARROSO E K L,GODEFROID L B.Fatigue crack growth analysis of pre-strained 7475-T7351aluminum alloy[J].International Journal of Fatigue,2006,28(8):934-942.
[9]唐振廷.GB/T 19748-2005《钢材夏比V型缺口摆锤冲击试验仪器化试验方法》实施指南[M].北京:中国标准出版社,2006.
[10]DIN EN ISO 4287:2010,Geometrical product specifications(GPS)-surface texture:Profile method-terms,definitions and surface exture parameters[P].International Organization for Standardization,Switzerland,2010.
[11]KOBAYASHI T,YAMAMOTO I,NIINOMI M.Introduction of a new dynamic fracture toughness evaluation system[J].Journal of Testing&Evaluation,1993,21,3(3):145-153.