Pub Date : 2013-10-01DOI: 10.1002/9781118787922.CH1
E. Hornbogen
Precipitation hardening of aluminum was discovered about 100 years ago by Dr. Alfred Wilm [1,2]. Using aluminum alloys as example a survey is given on mechanism and limits of precipitation hardening. It is discussed how hard, nanometer-size particles (nanos, greek, the dwarf) can form as an ultra fine dispersoid. A simple example for optimum conditions is provided by diamond cubic particles (Si, Ge) in the f.c.c. Al-Matrix. The role of a sequence from more to less metastable phases is discussed, as well as the effects of additional (and trace) alloying elements. The amount of precipitation hardening is limited, besides by the volume fraction of particles, by their strength. This in turn determines the critical diameter above which the transition from passing to by-passing by dislocations takes place. Simple models for the calculation of this microstructural parameter are discussed. From combinations of precipitation hardening with other hardening mechanisms the limits for ultra high strengths are defined.
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Pub Date : 2008-01-01DOI: 10.1002/9783527627110.ch13
S. Kalinichenka, H. Weidmüller, T. Weissgärber, B. Kieback, C. Kirchberger, H. Kau
{"title":"Neuartige kupfer-PCM-Verbundwerkstoffe für Anwendungen im Bereich des thermischen Managements","authors":"S. Kalinichenka, H. Weidmüller, T. Weissgärber, B. Kieback, C. Kirchberger, H. Kau","doi":"10.1002/9783527627110.ch13","DOIUrl":"https://doi.org/10.1002/9783527627110.ch13","url":null,"abstract":"","PeriodicalId":35782,"journal":{"name":"Metall","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83420422","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}
The steadily growing demand for copper and copper alloy products and the increasing cost pressure on metal manufacturers in a global competition demand for an increase of productivity and plant availability, optimization of product quality and quality assurance and a cut of production costs. These demands represent a particular challenge to the casting process, usually the first step in the production chain. In order to meet or even exceed the above-mentioned demands it is obligatory to apply equipment, which incorporates the most economic and efficient technology. Although the horizontal continuous casting process is well established for the production of brass billets, it offers sufficient chances for further development. These chances are the drive for the research and development activities of Demag Technica, a subsidiary of SMS Meer GmbH. It is an ISO 9000 certified manufacturer of continuous casting equipment predominately for the copper and copper alloy industry. Nowadays horizontal continuous casting plants are capable of producing billets up to 400 mm diameter in single or multiple strand operation. It is realized however that the tendency, particularly for leaded brasses, goes towards casting larger billet diameters and multiple strand operation. With the example of two recently supplied horizontal continuous casting plants it is outlined how the developments of Demag Technica contribute to the raise of competitiveness of its customers. .
在全球竞争中，对铜和铜合金产品的需求稳步增长，金属制造商的成本压力不断增加，需要提高生产率和工厂可用性，优化产品质量和质量保证，降低生产成本。这些要求代表了铸造工艺的特殊挑战，通常是生产链的第一步。为了达到甚至超过上述要求，必须采用最经济、最高效的技术。虽然水平连铸工艺在生产黄铜小方坯方面已经很成熟，但它仍有充分的发展空间。这些机遇推动了SMS Meer GmbH子公司Demag Technica的研发活动。它是一家ISO 9000认证的连铸设备制造商，主要用于铜和铜合金行业。如今，卧式连铸厂能够在单股或多股操作中生产直径达400毫米的钢坯。然而，人们认识到，特别是含铅黄铜的趋势是铸造更大的钢坯直径和多股操作。以最近提供的两家卧式连铸厂为例，概述了德马格技术公司的发展如何有助于提高其客户的竞争力。
{"title":"Horizontal Continuous Casting of Copper Alloy Billets","authors":"M. Brey","doi":"10.1002/3527607331.CH48","DOIUrl":"https://doi.org/10.1002/3527607331.CH48","url":null,"abstract":"The steadily growing demand for copper and copper alloy products and the increasing cost pressure on metal manufacturers in a global competition demand for an increase of productivity and plant availability, optimization of product quality and quality assurance and a cut of production costs. These demands represent a particular challenge to the casting process, usually the first step in the production chain. In order to meet or even exceed the above-mentioned demands it is obligatory to apply equipment, which incorporates the most economic and efficient technology. Although the horizontal continuous casting process is well established for the production of brass billets, it offers sufficient chances for further development. These chances are the drive for the research and development activities of Demag Technica, a subsidiary of SMS Meer GmbH. It is an ISO 9000 certified manufacturer of continuous casting equipment predominately for the copper and copper alloy industry. Nowadays horizontal continuous casting plants are capable of producing billets up to 400 mm diameter in single or multiple strand operation. It is realized however that the tendency, particularly for leaded brasses, goes towards casting larger billet diameters and multiple strand operation. With the example of two recently supplied horizontal continuous casting plants it is outlined how the developments of Demag Technica contribute to the raise of competitiveness of its customers. .","PeriodicalId":35782,"journal":{"name":"Metall","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85261819","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}
Pub Date : 2006-03-01DOI: 10.21608/jesaun.2006.110475
A. A. Omar, A. Kandil
The corrosion behavior of the cast Zn-4Al and Si/ (Zn-4Al) alloys when attacked by 3.5 % NaCl solution at different temperatures, 31, 40, 50, and 60 °C was investigated. The Tafel intercept logarithmic polarization methods were utilized for determining the corrosion parameters. Some corrosion kinetic and mechanistic parameters hare been studied in the absence and presence of various concentrations of K 2 CrO 4 . The study indicated that the percentage inhibition efficiency increased with the increase of the inhibitor concentration and decreased with the increase of solution temperature. The activation energy of corrosion increased with the increase of both the corrosion rate and temperature. The addition of Si particles into Zn-4Al can greatly improve the corrosion resistance and has a significant effect on the Tafel polarization measurements. The corrosion resistance increases with increasing the volume fraction of Si-Particles.
{"title":"The corrosion behaviour of Zn-4Al (AC43A) and Sip(Zn-4Al) composites in an artificial sea water","authors":"A. A. Omar, A. Kandil","doi":"10.21608/jesaun.2006.110475","DOIUrl":"https://doi.org/10.21608/jesaun.2006.110475","url":null,"abstract":"The corrosion behavior of the cast Zn-4Al and Si/ (Zn-4Al) alloys when attacked by 3.5 % NaCl solution at different temperatures, 31, 40, 50, and 60 °C was investigated. The Tafel intercept logarithmic polarization methods were utilized for determining the corrosion parameters. Some corrosion kinetic and mechanistic parameters hare been studied in the absence and presence of various concentrations of K 2 CrO 4 . The study indicated that the percentage inhibition efficiency increased with the increase of the inhibitor concentration and decreased with the increase of solution temperature. The activation energy of corrosion increased with the increase of both the corrosion rate and temperature. The addition of Si particles into Zn-4Al can greatly improve the corrosion resistance and has a significant effect on the Tafel polarization measurements. The corrosion resistance increases with increasing the volume fraction of Si-Particles.","PeriodicalId":35782,"journal":{"name":"Metall","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2006-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77235245","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}
Pub Date : 1907-12-31DOI: 10.1515/9783112510766-008
{"title":"7.Metallarbeiten aus dem Orient und Osteuropa","authors":"","doi":"10.1515/9783112510766-008","DOIUrl":"https://doi.org/10.1515/9783112510766-008","url":null,"abstract":"","PeriodicalId":35782,"journal":{"name":"Metall","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1907-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79693286","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}
Pub Date : 1907-12-31DOI: 10.1515/9783112510766-006
{"title":"4. Zinn und Blei","authors":"","doi":"10.1515/9783112510766-006","DOIUrl":"https://doi.org/10.1515/9783112510766-006","url":null,"abstract":"","PeriodicalId":35782,"journal":{"name":"Metall","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1907-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77741043","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}
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