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Al composite materials
This section contains abstracts of selected English language articles, technical reports, dissertations and patents concerned with fatigue. It is prepared in collaboration with Materials Information, a joint service of The Institute of Metals and ASM International. Readers wishing to obtain the full text of articles abstracted here should contact either: The Institute of Metals, 1 Carlton House Terrace, London SWlY 5DB, UK, or: ASM International, Metals Park, OH 44073, USA (not hernational Journal of fatigue). The fees charged for photocopying articles are f7.00 for the first ten pages and f3.00 per additional ten pages (UK office), or $10.00 for the first ten pages and $4.00 per additional ten pages (US office). Composites Fibre FP/matal matrix composite connecting rods: design, fabrication and performance, Fo/gar, F. &ram. Eng. Sci. Boc. July-Aug. 198B.9, (7-9). 991-579 Aluminium and magnesium castings reinforced with fibre FP. Du Pant’s aluminia fibre. are being developed for high-performance automotive applications. The connecting rod has been selected as the model to assess the value of these reinforced castings and to develop design and fabrication technology. While they are lighter and may offer better compressive strength and stiffness and fatigue resistance than conventional engine materials, their design sitll represents a major technical Challenge. A comparative study was undertaken to predict the structural behaviour of conrwcting rods using two- and threedimensional finite element stress analysis models, and to detenine the most cost effective modelling and analysis approach. Results from all the analyses match closely and correlate well with static and fatiaue testing of FP/AI and Fp/Ma cast connectina rods. A useful alloy composition. castins conditio& and machining techniques are disc&d. Computerized industrial tomography is identified as a reliable method of determining casting quality 9 refs
The crystallographic and fractographic aspects of stage I corrosion fatigue of SS 316L have been studied with the aid of etch pitting techniaues Single edge notch specimens were fatigued at 123 Hz in desiccated air and near neu&al (PH 55) aqueous environments of 1 M N&l + 0.01 M Na,S,O,. The fractographic features were found to be independent of the testing conditions. The orientation of primary facets and tha clystallographic directions of crack propagation were identified. Six combinations of crack plane and direction were observed with orimarv facet orientations of 111. 110. and 001. The orimaw facet cwstallography was &own to arise from microscale propagation along a’ single iaiiani ‘of 111 or alternating periods of microscale propagation along a conjugate pair of 111 variants. The mechanism of cracking was discussed and shown to be consistent with a model of restricted slip reversibility (RSR). where environmental interactions with emergent slip steps influence the amount of slip reversibility 30 refs.
High frequency stage I corrosion fatigue of sustenitic stainleas steel @ML). Fong, C. and Tkmans, D. Metal/. Tmns. A Nov. 1999,19A, (11). 2753-2794
Torsion-type internal friction measurements by forced vibrations out of resonance were developed and application to long-fibre-reinforced composite materials. PCS-type Sic/ Al 050 Al comtxsites. was studied. From strain amplitude dependence. the activation enerw for dislocation break-away from pinning points was obtained. The grain boundary peak of Al was suppressed in SIC/AI composites A damping peak. interpreted to be due to the ir&faee.~.wes mn&tre&&~r 0.07 Hz at 300 K and the effect of thermal treatment on the peak was inv&ti~%d: At stress levels higher than the break-away stress. internal friction values changed with vibrating cycles and this behaviour is interpreted to provide initial and elemental processes of fatigue. 15 refs.
High frequency (123 Hz) fatigue crack propagation studies were conducted under rising AK condmons (R-ratio = 0 22) on single edge notch specimens of austenitic stainless steel (type 316L) that contamed an annealed precrack Tests were conducted in near neutral (pH 5.5) solutmns of 1 M N.&l and 1 M NaCl + 0 01 M Na,S*O, under potentiostatically controlled conditions and in desiccated air. Attention was directed primarily to the near threshold behaviour and the staQe I (crystallographic) region of cracking. Good mixing between the crack solution and bulk solution was obtained and crack retardation and arrest effects. due to surface roughness induced closure, were minimized at high anodic potentials by electrochemical erosion Thermodynamic considerations showed that hydrogen played no role !n fatigue crack propagation Analysis of the results in terms of the estimated effective cyclic stress intensity. &a, showed a systematic eff%ct of potential on the average crack growth increment/cycle. da/dN. Anodic dissolution processes were considered to make an insignificant contribution to da/dN. A model was proposed for stage I fatigue cracking based on the effect of oxide nucleation rate on restricted Slip reversal. The essential features of the model were considered to be relevant to cracking in aoueous environments and in desiccated air 45 refs.
Damage toleranw and rupportability aspects of ARALL laminate aircraft structures. Gunnink,J. W compos. struct. 1988,10, (1). 83-104
Corrosion fatigue ouch armst in aluminium Wanhill, R.J. ii and Wwa, L. Report No. NLR TR 87128 U
Comparison of ARALL @amid Al) laminates with other aircraft materials on a structural level shows that ARALL laminate is a very attractive material, especially for fatigue dominated stfuctural InvestiQation of this material in relation to the primary aircraft allowables gives soma remarkable results. Fatigue and static testing of an ARALL F-27 kwer wing panel confirms this. 16 refs.
Constant amplitude low stress intensity fatigue crack ~rcwth for 2024-T3 and 7476-T761 Al allow in laboratory air. sump tank water and synthetic seawater was investigated. Corrosion fatigue crack grovdh retardation and in both sump tank water and synthetic seawater. resulting in higher AK& values than in air. Crack arrest was due to crack blocking by corrosion product layers. Enhancing crack arrest. and hence the durability of aircraft strwtwes. appears to be feasible. 61 refs
Application of intomal friction mwsurwnonta to Sic/AI compoaita nwtulak. Twk H., Saito, S., Kohyann~,A and lgata, N. J. NucL Matw. July 19S9,186197A, 3M-343
pms.
Fractura mechanics of delamination in ARALL laminates. Yeh, J.R. Eng. Fmct. Mech. 1986,30, (6). 027937 Fracture mechanics of delamination in ARALL laminates (aramid fibreI7075 Al alloy) 1s examined bv using a finite element method employing special singular elements. Since these special elements contain the exact stress singularity, the delamination stress intensity factors and energy release rates can be evaluated convenientlv. Solution convergence is studied to demonstrate the efficiencv of this method. To ensure the validitv of the result. the numeric prediction is cornpa& with experimental results. Van/ good agreement is obtained. 20 refs.
Corrosion variousoloctroch8nliil f$!ti~n~.C~M~$),~
mnaummont8 in a simulatul J. and f%Mns, R.N.
corrooion
Measurements of potential. current. pH. and chloride ion concentration were made along a simulated corrosion fatigue crack for HYBO (UNS K31620) steel in seawater. The simulated crack yields results comparable with those from real cracks and allows predictions of potential gradients to be made. The results show that movement of the-crevice sides to promote pumping does not cause significant solution refreshments within the enclave at frequencies of 0.1 and 0.02 Hz. but flow across the mouth does alter the solution chemisty These results have been strengthened by diffusion experiments in the crevice. No detectable chloride ion concentration gradients were found in the enclave across the potential range examined. 11 refs.
I corm&n fatifjuo craok cfyatallogmphy in wstonitii stainloa ~SlSL,.Fong,C.andTromawD. Metell.Trans. 4 Nov. 1988, WA, (11), 2795-2773
alloys: bask
data.
meatoccurred
Corrosionfatigw.
Schutz, W lnt. J. Mater. Pmd. Tachnol. 1988.3, (1). 20-37
The parameters influencing corrosion are discussed in a general way, making use of results obtained bv the author as well as bv sewral international corrosion fatigue test prooremmes. Only the detrimental effects of a&ficial sea water. tap water and boiler fe& hater on steels and Al alloys are considered. These parameters are: test frequency and/or time in the environment. corrosive environment; stress level and stress sequence: crack initiation and/or crack propagation: materials: type of test specimen: protection systems. Urgent but unsolved problems in corrosion fatigue are mentioned. 96 refs.
mmochanioml ldmtia of stroctur8l steel in *mt~~~N~-tlPenvlronmenm. Tumbull, A, da Santa h&n& M.S. Convs Sci. lti,~zS.
(10). 1029-1038
Anodic and cathodic polarization studies have been conducted on the shwtural steel BS 4360 50D in de-aerated solutions of NaCl and FaCI, owr a range of concentrations and pH values. The environments investigated embraced the conditions pmdii at the tip of a fatigue crack when this steel is corroding in sea water. Precipitation of ferrous hydroxide as the pH of 3.5% NaCl containing ferrous chloride was inuaased caused a significant decrease in the anodic current density relative to values obtained in 3.5% N&I. The cathodic reduction of ferrous ions was also suppressed by the precipitate film even at a nominal bulk pH of 4. The precipitate film is thus acting as both an anodic and cathodic inhibitor. 6 refs.
Motallu ial tiilurw on off8horo oil production inbllations. P&S&R. Mat. Matar Sept. 19BB, 4, (9). 399-994
N&on,
Offshore oil installations incorporate Complex drilling. production and ultilittes svstems. In-
Int J Fatigue May 1989
The crystallographic and fractographic aspects of stage I corrosion fatigue of SS 316L have been studied with the aid of etch pitting techniaues Single edge notch specimens were fatigued at 123 Hz in desiccated air and near neu&al (PH 55) aqueous environments of 1 M N&l + 0.01 M Na,S,O,. The fractographic features were found to be independent of the testing conditions. The orientation of primary facets and tha clystallographic directions of crack propagation were identified. Six combinations of crack plane and direction were observed with orimarv facet orientations of 111. 110. and 001. The orimaw facet cwstallography was &own to arise from microscale propagation along a’ single iaiiani ‘of 111 or alternating periods of microscale propagation along a conjugate pair of 111 variants. The mechanism of cracking was discussed and shown to be consistent with a model of restricted slip reversibility (RSR). where environmental interactions with emergent slip steps influence the amount of slip reversibility 30 refs.
High frequency stage I corrosion fatigue of sustenitic stainleas steel @ML). Fong, C. and Tkmans, D. Metal/. Tmns. A Nov. 1999,19A, (11). 2753-2794
Torsion-type internal friction measurements by forced vibrations out of resonance were developed and application to long-fibre-reinforced composite materials. PCS-type Sic/ Al 050 Al comtxsites. was studied. From strain amplitude dependence. the activation enerw for dislocation break-away from pinning points was obtained. The grain boundary peak of Al was suppressed in SIC/AI composites A damping peak. interpreted to be due to the ir&faee.~.wes mn&tre&&~r 0.07 Hz at 300 K and the effect of thermal treatment on the peak was inv&ti~%d: At stress levels higher than the break-away stress. internal friction values changed with vibrating cycles and this behaviour is interpreted to provide initial and elemental processes of fatigue. 15 refs.
High frequency (123 Hz) fatigue crack propagation studies were conducted under rising AK condmons (R-ratio = 0 22) on single edge notch specimens of austenitic stainless steel (type 316L) that contamed an annealed precrack Tests were conducted in near neutral (pH 5.5) solutmns of 1 M N.&l and 1 M NaCl + 0 01 M Na,S*O, under potentiostatically controlled conditions and in desiccated air. Attention was directed primarily to the near threshold behaviour and the staQe I (crystallographic) region of cracking. Good mixing between the crack solution and bulk solution was obtained and crack retardation and arrest effects. due to surface roughness induced closure, were minimized at high anodic potentials by electrochemical erosion Thermodynamic considerations showed that hydrogen played no role !n fatigue crack propagation Analysis of the results in terms of the estimated effective cyclic stress intensity. &a, showed a systematic eff%ct of potential on the average crack growth increment/cycle. da/dN. Anodic dissolution processes were considered to make an insignificant contribution to da/dN. A model was proposed for stage I fatigue cracking based on the effect of oxide nucleation rate on restricted Slip reversal. The essential features of the model were considered to be relevant to cracking in aoueous environments and in desiccated air 45 refs.
Damage toleranw and rupportability aspects of ARALL laminate aircraft structures. Gunnink,J. W compos. struct. 1988,10, (1). 83-104
Corrosion fatigue ouch armst in aluminium Wanhill, R.J. ii and Wwa, L. Report No. NLR TR 87128 U
Comparison of ARALL @amid Al) laminates with other aircraft materials on a structural level shows that ARALL laminate is a very attractive material, especially for fatigue dominated stfuctural InvestiQation of this material in relation to the primary aircraft allowables gives soma remarkable results. Fatigue and static testing of an ARALL F-27 kwer wing panel confirms this. 16 refs.
Constant amplitude low stress intensity fatigue crack ~rcwth for 2024-T3 and 7476-T761 Al allow in laboratory air. sump tank water and synthetic seawater was investigated. Corrosion fatigue crack grovdh retardation and in both sump tank water and synthetic seawater. resulting in higher AK& values than in air. Crack arrest was due to crack blocking by corrosion product layers. Enhancing crack arrest. and hence the durability of aircraft strwtwes. appears to be feasible. 61 refs
Application of intomal friction mwsurwnonta to Sic/AI compoaita nwtulak. Twk H., Saito, S., Kohyann~,A and lgata, N. J. NucL Matw. July 19S9,186197A, 3M-343
pms.
Fractura mechanics of delamination in ARALL laminates. Yeh, J.R. Eng. Fmct. Mech. 1986,30, (6). 027937 Fracture mechanics of delamination in ARALL laminates (aramid fibreI7075 Al alloy) 1s examined bv using a finite element method employing special singular elements. Since these special elements contain the exact stress singularity, the delamination stress intensity factors and energy release rates can be evaluated convenientlv. Solution convergence is studied to demonstrate the efficiencv of this method. To ensure the validitv of the result. the numeric prediction is cornpa& with experimental results. Van/ good agreement is obtained. 20 refs.
Corrosion variousoloctroch8nliil f$!ti~n~.C~M~$),~
mnaummont8 in a simulatul J. and f%Mns, R.N.
corrooion
Measurements of potential. current. pH. and chloride ion concentration were made along a simulated corrosion fatigue crack for HYBO (UNS K31620) steel in seawater. The simulated crack yields results comparable with those from real cracks and allows predictions of potential gradients to be made. The results show that movement of the-crevice sides to promote pumping does not cause significant solution refreshments within the enclave at frequencies of 0.1 and 0.02 Hz. but flow across the mouth does alter the solution chemisty These results have been strengthened by diffusion experiments in the crevice. No detectable chloride ion concentration gradients were found in the enclave across the potential range examined. 11 refs.
I corm&n fatifjuo craok cfyatallogmphy in wstonitii stainloa ~SlSL,.Fong,C.andTromawD. Metell.Trans. 4 Nov. 1988, WA, (11), 2795-2773
alloys: bask
data.
meatoccurred
Corrosionfatigw.
Schutz, W lnt. J. Mater. Pmd. Tachnol. 1988.3, (1). 20-37
The parameters influencing corrosion are discussed in a general way, making use of results obtained bv the author as well as bv sewral international corrosion fatigue test prooremmes. Only the detrimental effects of a&ficial sea water. tap water and boiler fe& hater on steels and Al alloys are considered. These parameters are: test frequency and/or time in the environment. corrosive environment; stress level and stress sequence: crack initiation and/or crack propagation: materials: type of test specimen: protection systems. Urgent but unsolved problems in corrosion fatigue are mentioned. 96 refs.
mmochanioml ldmtia of stroctur8l steel in *mt~~~N~-tlPenvlronmenm. Tumbull, A, da Santa h&n& M.S. Convs Sci. lti,~zS.
(10). 1029-1038
Anodic and cathodic polarization studies have been conducted on the shwtural steel BS 4360 50D in de-aerated solutions of NaCl and FaCI, owr a range of concentrations and pH values. The environments investigated embraced the conditions pmdii at the tip of a fatigue crack when this steel is corroding in sea water. Precipitation of ferrous hydroxide as the pH of 3.5% NaCl containing ferrous chloride was inuaased caused a significant decrease in the anodic current density relative to values obtained in 3.5% N&I. The cathodic reduction of ferrous ions was also suppressed by the precipitate film even at a nominal bulk pH of 4. The precipitate film is thus acting as both an anodic and cathodic inhibitor. 6 refs.
Motallu ial tiilurw on off8horo oil production inbllations. P&S&R. Mat. Matar Sept. 19BB, 4, (9). 399-994
N&on,
Offshore oil installations incorporate Complex drilling. production and ultilittes svstems. In-
Int J Fatigue May 1989