稀有金属材料与工程
稀有金屬材料與工程
희유금속재료여공정
RARE METAL MATERIALS AND ENGINEERNG
2007年
12期
2119-2123
,共5页
崔伟华%万建松%岳珠峰%杨治国
崔偉華%萬建鬆%嶽珠峰%楊治國
최위화%만건송%악주봉%양치국
镍基粉末冶金FGH95合金%拉伸性能%低周疲劳%应变率影响%温度效应%断裂模式
鎳基粉末冶金FGH95閤金%拉伸性能%低週疲勞%應變率影響%溫度效應%斷裂模式
얼기분말야금FGH95합금%랍신성능%저주피로%응변솔영향%온도효응%단렬모식
nickel-base powder metallurgy superalloy FGH95%tensile property%low cycle fatigue%strain rate effect%temperature effect%fracture mode
在420～650℃的温度范围内,研究了PM FGH95高温合金在应变率0.0001～0.01 s-1范围内的拉伸性能及在不同应力比R=-1及R=0下的低周疲劳性能.拉伸试验结果表明:在此温度范围内,应变率对弹性模量、拉伸屈服强度及塑性模量的影响可以忽略不计;并且应变率自0.0001 s-1增大至0.01 s-1时,弹性模量、拉伸屈服强度及塑性模量受温度的影响也不明显.PM FGH95合金受材料微结构的影响很大,材料含有的微缺陷对其力学性能有非常不利的影响.LCF试验结果表明:PM FGH95合金是循环硬化材料.当应力比R=-1时,温度对LCF寿命的影响很小;但在应力比R=0时,LCF寿命受温度的影响很大,且随着温度的增加材料的低周疲劳寿命减小.SEM断口扫描发现,断裂表面有很多的解理面,但没有疲劳条带,且此断裂模式下没有明显的塑性变形,所以FGH95合金的低周疲劳寿命几乎是由裂纹萌生阶段决定的.
在420～650℃的溫度範圍內,研究瞭PM FGH95高溫閤金在應變率0.0001～0.01 s-1範圍內的拉伸性能及在不同應力比R=-1及R=0下的低週疲勞性能.拉伸試驗結果錶明:在此溫度範圍內,應變率對彈性模量、拉伸屈服彊度及塑性模量的影響可以忽略不計;併且應變率自0.0001 s-1增大至0.01 s-1時,彈性模量、拉伸屈服彊度及塑性模量受溫度的影響也不明顯.PM FGH95閤金受材料微結構的影響很大,材料含有的微缺陷對其力學性能有非常不利的影響.LCF試驗結果錶明:PM FGH95閤金是循環硬化材料.噹應力比R=-1時,溫度對LCF壽命的影響很小;但在應力比R=0時,LCF壽命受溫度的影響很大,且隨著溫度的增加材料的低週疲勞壽命減小.SEM斷口掃描髮現,斷裂錶麵有很多的解理麵,但沒有疲勞條帶,且此斷裂模式下沒有明顯的塑性變形,所以FGH95閤金的低週疲勞壽命幾乎是由裂紋萌生階段決定的.
재420～650℃적온도범위내,연구료PM FGH95고온합금재응변솔0.0001～0.01 s-1범위내적랍신성능급재불동응력비R=-1급R=0하적저주피로성능.랍신시험결과표명:재차온도범위내,응변솔대탄성모량、랍신굴복강도급소성모량적영향가이홀략불계;병차응변솔자0.0001 s-1증대지0.01 s-1시,탄성모량、랍신굴복강도급소성모량수온도적영향야불명현.PM FGH95합금수재료미결구적영향흔대,재료함유적미결함대기역학성능유비상불리적영향.LCF시험결과표명:PM FGH95합금시순배경화재료.당응력비R=-1시,온도대LCF수명적영향흔소;단재응력비R=0시,LCF수명수온도적영향흔대,차수착온도적증가재료적저주피로수명감소.SEM단구소묘발현,단렬표면유흔다적해리면,단몰유피로조대,차차단렬모식하몰유명현적소성변형,소이FGH95합금적저주피로수명궤호시유렬문맹생계단결정적.
The tensile behavior of a nickel-base powder metallurgy(PM)FGH95 superalloy was studied in the temperature range from 420℃ to 650℃ with strain rate from 0.0001 s-1 to 0.01 s-1.The low cycle fatigue(LCF)behavior of this superalloy was investigated in the temperature range from 420℃ to 650℃ under push-pull mode(R=-1)and pull mode (R=0)at strain rate of 0.001 S-1.The results of tensile testing show that the effect of strain rate on the Young's modulus,tensile yield strength,and plastic modulus can be neglected in the experimental temperature range.And the influence of temperature on the Young's modulus,tensile yield strength,and plastic modulus is not obvious in the strain rate range from 0.000 1 s-1 to O.01 s-1.The PM FGH95 is sensitive to the micro-defect.which has a significant deleterious effect on FGH95 material mechanical behavior.The results of LCF reveal that the PM FGH95 is the cyclic hardening material.For mode R=-1.the effect of temperature on LCF life can be neglected;but for mode R=0,the temperature has profound influence on the LCF life.At this case,the LCF life decreases drastically with the temperature increasing.The SEM investigation of LCF specimens shows that there are a lot of cleavages on fracture surface,fatigue striations are absent,and this fracture mode may not involve significant plastic deformation.So the LCF life of PM FGH95 is almost determined by the crack initiation stage.
