灰色关联分析在腐蚀非晶态镍基合金中的应用

用灰色关联分析方法取代传统的数理统计方法,对非晶态镍基合金在FeCl_3溶液中的腐蚀速率与影响因素之间的相互关系进行处理,确定各影响因子之间的主次关系。结果表明溶液流速是最关键因子,次关键因子为溶液pH值,其次为溶液温度和溶液浓度,并根据分析结果提出实际应用时的相应对策。     

Failure analysis of a hot extrusion die used for Al-Li alloy processing

Al-Li alloys being developed as lighter, substitutes for conventional high strength Al alloys are to be processed by routine methods. During extrusion of a 8090 Al-Li alloy, the extrusion die container failed causing some alarm. This failed die container was analysed to examine if the failure was caused by interaction of Li diffusing out of Al-Li alloy with the carbides of die steel. The evidence, although not conclusive, is sufficient to exercise caution during such processing.     

A numerical model for the dissolution of spherical particles in binary alloys under mixed mode control

A general numerical model is described for the dissolution kinetics of spherical particles in binary systems for any combination of first order reactions at the particle-matrix interface and long distance diffusion within the matrix. The model is applicable to both finite and infinite media and handles both complete and partial particle dissolution. It is shown that interfacial reactions can have a strong effect on the dissolution kinetics, the solute concentration at the particle-matrix interface and the solute concentration profile in the matrix.     

Peculiarities of erosion-corrosion processes

Investigations have been carried out on an erosion-corrosion apparatus to investigate the behaviour of corrosion-resistant highalloy iron-base materials containing hard phases. These materials had been optimized for increased wear resistance under complex stress conditions. As expected, in dry erosion tests, very low mass losses were established; there was little difference between the materials. Also, in corrosive environments (NaCl, H₂SO₄), the materials showed good stability; however, the duplex structures were superior to the martensitic ones. The combination of erosion and corrosion produced large differences and, in some cases, markedly reduced resistance to damage. These results confirmed observations that it is impossible to deduce the environmentally influenced mechanical behaviour of an alloy from its behaviour in separate corrosion and erosion experiments. The basic mechanisms underlying these processes have been investigated only tentatively.     

ESR Refining Potential for Titanium Alloys using a CaF2‐based Active Slag

Since the end of the Cold War and due to the needs to produce titanium more cost‐efficient and thus more attractive for its civilian use, the electroslag remelting (ESR) process has become an increasingly important topic of international research programmes, because titanium and titanium aluminides can be chemically refined by ESR in some degree. Using ESR, titanium turnings from machining steps and scrap from foundries can be remelted, refined and provided as secondary titanium for the market at relatively favourable prices. This article investigates the removability of the main impurities out of titanium and titanium‐aluminium alloys by electroslag remelting using the active slag system CaF₂‐Ca‐(CaO). Thermochemical and kinetic aspects of the ESR process are considered.     

Hydriding and Dehydriding Characteristics of Mechanically Alloyed LaMg_(17) Ni Composite Material

Magnesiumandmagnesiumalloyshavebeenin vestigatedashydrogenstoragematerialsforseveralde cadesbecausefarmorehydrogenbyweightcanbestoredinthemthaninmostoftheothercurrentlyknownhydrogenstoragealloys .Moreover ,thehighnaturalabundanceofMg ,itslightmassandenviron mentalcompatibilitypotentiallymakemagnesiumoneofthemostprospectivecandidatesforfuturehydrogenstoragematerials .Unfortunately ,thepracticalappli cationofMganditsalloyshasbeenlimitedonlytocertainstoragedevicebecauseoftheirpoorhydriding dehydr…