The effects of Ta additions on the phase compositions and high temperature properties of Pt base alloys

Rudnik, Yegor; Völkl, Rainer; Vorberg, Stefan; Glatzel, Uwe

doi:10.1016/j.msea.2007.06.066

Cited by 8 publications

(10 citation statements)

References 12 publications

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“…These differences were significant because they would affect the stabilities of the strengthening Pt 3 Al phases, as well as the amounts that could be produced. The German workers in the PDI collaboration (Fischer, 1992(Fischer, , 2001 Fischer et al 1997 Fischer et al 1999a Fischer et al , 1999bVölkl et al, 2000; Hüller et al, 2005;Rudnik et al, 2008;Vorberg et al, 2004Vorberg et al, , 2005Wenderoth et al, 2007) (Douglas et al, 2007) and showed some similarities to the modelled phase of Chauke et al (2010). The only difference was the purity of the raw materials: those of the Germans were much purer (Cornish and Chown, 2011).…”

Section: * Dst-nrf Centre Of Excellence In Strong Materialsmentioning

confidence: 94%

“…Three major ranges of Pt-based alloys have been developed. One is based on Pt-Al-Cr-Ni (Hüller et al, 2005;Wenderoth et al, 2005Wenderoth et al, , 2007Rudnik et al, 2008;Völkl et al, , 2009 and two are based on Pt-Al-Cr-Ru (Cornish et al, 2009a(Cornish et al, , 2009b Douglas et al, 2009). For the Pt-Al-CrRu alloys, one set was more malleable but less resistant to extreme chemical environments, whereas the other had higher chemical resistance, but was more difficult to form.…”

Section: * Dst-nrf Centre Of Excellence In Strong Materialsmentioning

confidence: 99%

“…These differences were significant because they would affect the stabilities of the strengthening Pt 3 Al phases, as well as the amounts that could be produced. The German workers in the PDI collaboration (Fischer, 1992(Fischer, , 2001Fischer et al 1997Fischer et al 1999aFischer et al , 1999bVölkl et al, 2000;Hüller et al, 2005;Rudnik et al, 2008;Vorberg et al, 2004Vorberg et al, , 2005Wenderoth et al, 2007) preferred McAlister andKahan's (1986) diagram, while the South African workers preferred the McAlister and Kahan (1986) diagram for most of the phase boundaries, but Oya et al's (1987) diagram for the temperatures of transformation of the Pt 3 Al phases. The structure of one lower temperature phase was derived (Douglas et al, 2007) and showed some similarities to the modelled phase of Chauke et al (2010).…”

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confidence: 99%

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PGMs: A cornucopia of possible applications

Cornish¹

2017

J. South. Afr. Inst. Min. Metall.

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South Africa has been mining PGMs for many years and has a vested interest in the usefulness of these metals, although originally, there was little thought about downstream beneficiation and some of the products were later purchased, in effect repurchasing the raw materials. However, for about 20 years, it has been realised that in order to build wealth sustainably, at least some of the beneficiation and development has to be done in South Africa. This is because for each stage of beneficiation, the value of the commodity increases and so to buy the PGMs back in a later state is uneconomical. Also, the industries need to be established here in South Africa, so that South Africans can work in them and become part of the workforce and generate their own wealth and sustainability for their families. This is part of the rationale of the AMI.In order to drive this, as well as a viable commercial strategy, with viable and wanted products, there has to be something different in the production mixture, for example, the product has to be better, new or cheaper. This is where research is used to try and develop new capabilities, or to improve them. PGMs, application, product development. PGMs: A cornucopia of possible applications and thermal conductivity of Pt are important (Fischer, 1992). Mechanically, Pt alloyed with rhodium or iridium combine high ductility with adequate creep strength and these properties give the alloys potential for applications in the chemical, space technology and glass industries (Fischer, 2001;Whalen, 1988; Lupton, 1990). In the spacecraft industry, PGMs are used to increase the heat resistance of rocket engine nozzles. A very important application is the manufacture of high-purity optical glasses and glass fibres by using platinum-containing tank furnaces, stirrers and feeders to withstand the high temperatures, mechanical loads and corrosive attack under the glass manufacturing and shaping conditions. In glasses, outstanding purity, homogeneity and the absence of bubble inclusions can be achieved only by using platinum alloys. If ceramic melting vessels were used, ceramic particles would be loosened by erosion, which would contaminate the glass melts and so compromise the desired optical properties such as transmittance. The alloys are expensive, but there are very few other materials that could replace platinum without risk of compromising the product. Thus, this is a valuable and safe use for platinum and some of its alloys. * DST-NRF Centre of Excellence in Strong MaterialsAnother 'standard use' of PGMs is in thermocouples and this arises because of their high electrical and thermal conductivity, as well as stability due to their high corrosion resistance. Typical alloys are Pt-Rh and Pt-Ru. The thermocouples do eventually degrade in aggressive environments and become brittle, but usually without much impairment of the electrical and conductive properties.A long-standing use of PGMs is in catalysts and South Africa has established an autocatalyst manufacturing and refurbishment plant for...

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Section: * Dst-nrf Centre Of Excellence In Strong Materialsmentioning

confidence: 94%

Section: * Dst-nrf Centre Of Excellence In Strong Materialsmentioning

confidence: 99%

“…These differences were significant because they would affect the stabilities of the strengthening Pt 3 Al phases, as well as the amounts that could be produced. The German workers in the PDI collaboration (Fischer, 1992(Fischer, , 2001Fischer et al 1997Fischer et al 1999aFischer et al , 1999bVölkl et al, 2000;Hüller et al, 2005;Rudnik et al, 2008;Vorberg et al, 2004Vorberg et al, , 2005Wenderoth et al, 2007) preferred McAlister andKahan's (1986) diagram, while the South African workers preferred the McAlister and Kahan (1986) diagram for most of the phase boundaries, but Oya et al's (1987) diagram for the temperatures of transformation of the Pt 3 Al phases. The structure of one lower temperature phase was derived (Douglas et al, 2007) and showed some similarities to the modelled phase of Chauke et al (2010).…”

mentioning

confidence: 99%

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PGMs: A cornucopia of possible applications

Cornish¹

2017

J. South. Afr. Inst. Min. Metall.

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“…Compressive proof stress results indicated better properties for Pt 74.5 :Hf 17 :Rh 8.5 (at.%) than the initial ternary alloys , but the oxidation resistance was much poorer. From these beginnings, two series of Pt-based alloys were developed: Pt-Al-Cr-Ru (Douglas et al, 2009;Cornish et al, 2009b) and Pt-Al-Cr-Ni (Hüller et al, 2005;Wenderoth et al, 2005Wenderoth et al, & 2007Rudnik et al, 2008;Völkl et al, 2005Völkl et al, & 2009. Both used the advantageous properties of aluminium (with the added benefit of chromium) for forming the ~Pt 3 Al precipitates and protective alumina films.…”

Section: Rationale For Developing Pt-based Superalloysmentioning

confidence: 99%

“…However, in the Pt-Al-Cr-Ni system, the dislocations were more similar to those in NBSAs , indicating that the Pt 3 Al precipitates were the fully cubic L1 2 allotrope. In studies on more complex alloys (Rudnik et al, 2008;Shongwe et al, 2008Shongwe et al, & 2010, it was found that the relationships between mechanical properties, precipitate size and misfit were difficult to quantify, as different elements acted differently at different compositions, and Ta actually reduced the ' amount at higher additions, even though it substituted for Al in ~Pt 3 Al (Rudnik et al, 2008). The only relationship that was obeyed was that misfit was related to the precipitate morphology, as stated by Qiu (1996).…”

Section: Pt-al-tamentioning

confidence: 99%