Journal of Metallurgy and Materials Science最新文献

{"title":"Optimization and crashworthiness investigation of empty and aluminium foam filled square tubes","authors":"R. Singh, Puneet Pawar","doi":"10.17706/IJMSE.2017.5.2.69-78","DOIUrl":"https://doi.org/10.17706/IJMSE.2017.5.2.69-78","url":null,"abstract":"Foam-filled thin-walled structures have drawn considerable attention and been widely applied in automotive and aerospace industries for their significant advantages in a high energy absorption and light weight. Recently the application of foam filled square tube in automobile industries has taken hike because of crashworthiness characteristic of foams. In the present study, energy absorption capacity of the empty (aluminum and mild steel) and foam in-filled (various aluminum alloys) square tubes have been numerically evaluated under car hitting condition. The finite element method (FEM) is applied in modeling the empty and foam-filled square tubes. The results show that the foam-filled square tubes have outstanding energy absorption characteristics under all the conditions considered. Based on the study results, best combination of materials in shell column wall and in-filled foam has been recommended.","PeriodicalId":16400,"journal":{"name":"Journal of Metallurgy and Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89188669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrosion protection of rebar steel in marine atmosphere by nanocoating","authors":"R. Singh, S. Misra","doi":"10.4172/2321-6212.1000113","DOIUrl":"https://doi.org/10.4172/2321-6212.1000113","url":null,"abstract":"Rebar steel is an important building material which is basically used for construction works. This metal is reinforced with concrete for construction of bridges and houses. Such types of bridges and houses face corrosive problems in coastal areas because high concentration of Cl− ions marine atmosphere. There are several porosities on the surface bridges and houses. The chloride ions enter inside the building materials and develop electrochemical cell on the surface of rebar steel. Rebar steel undergoes process of corrosion reaction and creates several forms of corrosion like galvanic, pitting, stress and crevice. Chlorides ions develop internal and external corrosive effect for rebar steel and concrete hence disbanding occur between building materials. This corrosive ion decreases life of building materials, increase maintenance costs and sometimes major accident takes place. The hydroxides of magnesium and calcium are present in concrete. Chloride ion reacts with these hydroxides and decreases the pH value of concrete thus accelerate the rate of corrosion reaction. Nanocoating of Mg3(PO4)2 with DLC filler is applied to control corrosion of rebar steel in marine atmosphere. The uncoated and coated rebar steel with Mg3(PO4)2 were exposed to marine atmosphere in different seasons like summer, rainy and winter. The corrosion rate of metal was analyzed in these seasons. The results show that though corrosion rate is minimized it does not produce good results. Porosities are developed on the surface of rebar steel coated with Mg3(PO4)2 which is reactive with chlorine ion. DLC is used as filler to close the porosities of coated rebar steel and again the corrosion rate of rebar steel was analyzed in the above mentioned seasons. It is found that this filler has good inhibition effect in marine atmosphere. The corrosion of metal was determined by gravimetric and potentiostatic polarization methods. Coating work was completed with application of nozzle sprays and vapour deposition methods. Coating efficiency, surface coverage area and stability of coating material were calculated with Arrhenius, Langmuir isotherm, Temkin equation, free energy, enthalpy and entropy.","PeriodicalId":16400,"journal":{"name":"Journal of Metallurgy and Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73606643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrosion behavior of heat treated nickel-aluminium bronze alloy in artificial seawater","authors":"M. Daroonparvara, M. M. Atabaki, A. Vakilipour","doi":"10.4236/msa.2011.211207","DOIUrl":"https://doi.org/10.4236/msa.2011.211207","url":null,"abstract":"The effect of microstructure of nickel-aluminum bronze alloy (NAB) on the corrosion behavior in artificial seawater is studied using linear polarization, impedance and electrochemical noise tests. The alloy was heat treated in different heating cycles including quenching, normalizing and annealing. Microstructure of the specimens was characterized before and after heat treatment by optical microscopy and scanning electron microscopy. Results showed that the value of pearlite phase in the normalized alloy is much more than other specimens, leading to higher corrosion resistance. Polarization test showed that starting point of passivation in the polarization of the normalized alloy is lower than other specimens. The dissolution of Mn and Fe rich phases increased the Mn and Fe contents in solid solution, and this enhanced the passivation power of the surface of the alloy. The effect of the alloying elements was seen by a lower corrosion potential and an inflexion at around 280 mV (SCE) in the polarization curve, indicating the preferential dissolution of some elements beyond that potential. The polarization curve showed that the anodic polarization behavior of the alloy in the solution was essentially controlled by the intermetallic phases, mainly containing Cu. Two types of corrosion, pitting and selective corrosion, were observed in the specimens after being exposed to artificial seawater.","PeriodicalId":16400,"journal":{"name":"Journal of Metallurgy and Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81690883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}