Grain refining response surfaces for three commercial aluminum alloys

Setzer, W.C.; Boone, G.W.; Wilson, Bill

doi:10.1016/b978-0-08-037295-2.50018-1

Cited by 7 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This suggests that the present transition is merely a morphological, rather than a structural, one. This is in agreement with earlier studies that report two types of AlB 2 crystals with low and high aspect ratios 18 – 22. Low aspect ratio AlB 2 is converted to high aspect ratio AlB 2 by heating above 950°C during the preparation of AlB 2 metal matrix composites,23 suggesting that the peritectic reaction occurs near 950°C 24.…”

Section: Resultssupporting

confidence: 92%

Improved halide salt process to produce Al–B master alloys

Birol

2011

Materials Science and Technology

View full text Add to dashboard Cite

Adding KBF4 salt to molten Al produces a B lean Al–B melt and a B rich dross. A revised practice that relies on the co-addition of Na3AlF6 with KBF4 and mechanical stirring is proposed in the present work to produce Al–B alloys. The highly surface active Na3AlF6 helps to break up the boride agglomerates glued together by the spent salt. Mechanical stirring facilitates uniform distribution of the freed borides in molten aluminium. The microstructural features of the Al–3B alloy thus processed and the B recovery were improved in a marked fashion. The boride dispersion in the aluminium matrix was uniform with no evidence of salt residues inside the aluminium matrix. An improved salt addition practice to ensure full B recovery and an Al–B alloy of sufficient quality is thus claimed to comprise the following steps: melting commercial purity aluminium ingot, adding premixed KBF4 and Na3AlF6 salts to molten Al at 800°C gradually to avoid excessive cooling of the melt, holding the melt for 5 min at 800°C to allow the reaction to reach completion, decanting the spent salt and throughly stirring the melt before casting into desired shape.

show abstract

Section: Resultssupporting

confidence: 92%

Improved halide salt process to produce Al–B master alloys

Birol

2011

Materials Science and Technology

View full text Add to dashboard Cite

show abstract

“…[8] Industrially, boron treatment has been employed to combine transition metals into their borides. [9][10][11][12] However, solution thermodynamic and reaction mechanism of borides formation are not well understood and further investigations are required. In this article a detailed thermodynamic analysis has been carried out to investigate the formation of borides.…”

mentioning

confidence: 99%

Thermodynamic Analysis of Ti, Zr, V and Cr Impurities in Aluminium Melt

Khaliq¹,

Rhamdhani²,

Brooks³

et al. 2011

Light Metals 2011

View full text Add to dashboard Cite

“…Industrially, impurities such as V, Ti, Zr, and Cr are removed in casthouse by the addition of boron bearing substances to the molten aluminum, known as boron treatment. [6][7][8][9][10][11][12][13][14][15][16] In the boron treatment of molten aluminum, Al-B master alloys are added in the form of waffles, ingots, or rods, depending on the process requirement and the required quality of the end product. Al-B master alloys containing AlB 2 or AlB 12 phases are commonly used in the industry.…”

Section: Introductionmentioning

confidence: 99%

“…Most of the laboratory studies focused on the increase of electrical conductivity by the addition of Al-B master alloys in molten aluminum. [1,2,[9][10][11]16,18] Process industrial trials focused on the use of AlB 12 or AlB 2 and the increase in electrical conductivity with reaction time. [6,8,12] Limited information is available regarding the kinetics and mass balance analysis of impurities during industrial boron treatment practices.…”

Section: Introductionmentioning

confidence: 99%

Removal of Vanadium from Molten Aluminum—Part III. Analysis of Industrial Boron Treatment Practice

Khaliq

Rhamdhani

Brooks

et al. 2014

Metall Mater Trans B

View full text Add to dashboard Cite

Transition metal impurities (V, Ti, Zr, and Cr) reduce the electrical conductivity of smelter grade aluminum. These impurities are removed in the form of their borides by reacting with added Al-B master alloys i.e., boron treatment. Although, boron treatment is widely used for the production of high purity aluminum alloys in casthouse the fundamental understanding is lacking and published industrial data are limited. In the current study, industrial trials on the removal of impurities were conducted at one of the high purity aluminum alloys producers in Australasia. Kinetics analysis revealed that the rate of reaction is controlled by the mass transfer of impurities in the bulk melt. The measured mass transfer coefficient (k m) of V and Ti were 1.1 9 10 À4 and 2.6 9 10 À4 m/s respectively, in the naturally stirred molten aluminum. The rate of V and Ti removal was faster compared to Zr and Cr during the boron treatment of smelter grade aluminum. Mass balance analysis revealed that 70 wt pct of V and Ti combined as borides in the first hour of the total 12 hours of boron treatment process. The calculated amount of un-reacted B was approximately 25.5 wt pct of initial amount added that remained in the final alloy. There was no evidence of boride rings formation, although partially dissolved AlB 12 particles were observed under scanning electron microscope. Finally, implications for industrial practice are discussed for the improvement of current boron treatment process that include changing the source of boron, multiple stage addition of boron and better stirring of the molten aluminum.

show abstract

Grain refining response surfaces for three commercial aluminum alloys

Cited by 7 publications

References 0 publications

Improved halide salt process to produce Al–B master alloys

Improved halide salt process to produce Al–B master alloys

Thermodynamic Analysis of Ti, Zr, V and Cr Impurities in Aluminium Melt

Removal of Vanadium from Molten Aluminum—Part III. Analysis of Industrial Boron Treatment Practice

Contact Info

Product

Resources

About