摘要:

AbstractThe characterisation of a design in terms of function, appearance, manufacturing method, and cost is considered. The interacting influences of design, fabrication, and materials selection are not always appreciated, which results in inefficiency or failure. This is considered in an historical setting, highlighting the changes in circumstance which now require better communication of information for such interaction to occur. The role of the computer in the provision of databases from standardised information and the development of‘intelligent’selector systems with input to models from consideration of microstructural engineering is outlined. The greatly increased range of materials to be considered and the need for integration of design, processing, and materials expertise, poses problems for the teaching of materials engineering where, again, the computer has an important role to play in developing understanding. In this very important area of industrial and educational endeavour, interaction should progress towards integration.MST/1063

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.509

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractInformation on material properties is essential to engineering design. The breadth and precision of the data that the designer requires depend on the stage the design has reached: at the start (the‘conceptual’stage), low level data for all materials; at the finish (the‘detailed design’stage), data at a high level of precision for one or a few materials. In this paper, a procedure for materials selection in mechanical design is described which allows the identification, from among the full range of materials available to the engineer, the subset most likely to perform best in a given application.MST/1064

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.517

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe liquidus temperatures along the monovariant trough running from the Cd–Cu–Cd3eutectic in each of the systems Cd–Cu–Zn, Cd–Cu–Mg, and Cd–Cu–Pb were determined using thermal and microstructural analyses. The solidus temperatures in the Cd–Cu–Mg system were also determined using thermal analysis. Alloys of monovariant composition in the Cd–Cu–Zn and Cd–Cu–Mg systems were found to have higher liquidus temperatures than the binary eutectic, indicating that the monovariant trough in these systems slopes down towards the binary eutectic. In the Cd–Cu–Pb system the liquidus temperatures along the monovariant were found to be lower than that of the binary eutectic. For the Cd–Cu–Zn system the present results are at variance with an earlier investigation.MST/579

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.526

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe structure and properties of Al–Li–Cu–Mg–Zr alloy AA 2091 in sheet form have been studied. Static and dynamic behaviour of material aged to the‘damage tolerant’category has been found to be at least equivalent to current BS L109 (AA 2024-T3) sheet while re-solution heat treatment did not appear to degrade properties. In contrast, although static strength parameters of stretched material aged to the‘medium strength’category were comparable with those of BS L157 (AA 2014-T6), re-solution heat treatment effected a noticeable decrease, with a failure to achieve 0·2%PS levels. Mechanical properties and subsequent fracture behaviour were correlated with submicrostructure throughout the investigation.MST/958

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.533

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractA parametric study has been carried out to quantify the recrystallised grain size in two commercial non heat treatable alloys, AA 5056 and AA 5083. It is shown that the deformation parameters (including total hot strain and deformation temperature) and the parent microstructures (typically quantified by grain size and constituent particles) have a controlling effect on recrystallised grain size. Grain growth subsequent to recrystallisation has also been studied as a function of time and temperature of annealing. Grain size distributions were also measured and are presented in the form of histograms.MST/899

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.542

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractThe emergence of lithium containing aluminium alloys as potential light metals for aircraft structures has engendered an unprecedented widespread interest aimed at improving their mechanical properties and studying their cyclic fatigue characteristics. The phenomenon of fatigue is environment sensitive and the alternating moisture conditions experienced by this candidate airframe material can be a handicap when designing for enhanced fatigue resistance. In this paper, the fatigue properties, deformation characteristics, and cyclic stress response of the commercial Al–Li–Cu–Mn and the experimental Al–Li–Mn and Al–Li–Cu–Mg–Zr alloys cycled to failure are compared over a range of plastic strain amplitudes in various environments, spanning the inert to the very aggressive. Abnormal plastic strain–fatigue life behaviour was observed for all the alloy systems and is attributed to differences in the distribution of deformation as a function of plastic strain amplitude and to change in the relative amounts of intergranular and transgranular fracture as a function of strain amplitude. Cyclic deformation was also observed to produce softening in the three alloys for most of their fatigue life. The softening is due to progressive loss of ordering contributions to hardening and is a mechanical and not an environmental effect.MST/888

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.548

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn equation for the half width of an adiabatic shear band formed under combined stresses is derived. The importance of strain rate, stress, temperature rise, and thermal conductivity is described. Confirmation is found for the proposition that shear band width is independent of stress state and this is confirmed by comparing the theory with the experimental results of other workers.MST/933

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.557

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractTo date it has been difficult to identify active material originating from the oxidation products of cladding alloys in the cooling circuits of power reactors. In an attempt to solve this problem, a sample of cladding oxide was characterized fully using secondary ion mass spectrometry (SIMS), exploiting the high sensitivity and ability of this technique to obtain chemical information from relatively small areas. However, if SIMS is to be used for analysis of fuel clad oxide, it is important that the required sensitivity factors be determined for the apparatus in which the analysis is to be carried out. For this reason, a number of Fe–Ni–Cr standard alloys were investigated to obtain sensitivity factors for the PHI Perkin-Elmer Model 3500 SIMS II apparatus. The values obtained were then used for the analysis of 20Cr–25Ni–Nb fuel clad material and its oxide.MST/821

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.560

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractAn investigation has been carried out to identify the precipitates in multiple microalloyed steels. The microalloying elements and interstitials included aluminium, niobium, titanium, vanadium, carbon, and nitrogen. It was found that the precipitates are complex in nature and they were rationalised on the basis of mutual solubility probably enhanced by non-stoichiometry. The precipitate morphologies were interpreted mainly in terms of steel compositions. Steels quenched from 1250°C contained titanium rich precipitates accompanied by the evolution of new niobium rich precipitates after hot rolling and quenching. A parameter K1indicative of solute participation in the precipitation phenomenon was established and showed excellent correlation between steel and precipitate analyses. A sequence of precipitation in multiple microalloyed steels was achieved using solubility relationships as a premise.MST/803

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.566

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

AbstractSteels containing various combinations of microalloying elements (Nb, V, and Ti) were welded at heat inputs from 3 to 6 kJ mm−1. It was shown by detailed crack tip opening displacement fracture toughness testing of coarse grained heat affected zone (HAZ) regions in single pass weld deposits that the poorest toughness properties were exhibited by steel containing a combination of Nb, V, and Ti. Steel microalloyed with only titanium had the best HAZ fracture toughness at all heat input levels. Detailed microstructural analysis, grain size measurement, hardness, and precipitation in HAZ regions were evaluated to explain the fracture toughness properties observed.MST/887

ISSN:0267-0836    

DOI:10.1179/mst.1989.5.6.575

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor