miun.sePublikasjoner
Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Hot tearing susceptibility of AA3000 aluminum alloy containing Cu, Ti, and Zr
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.
Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap.ORCID-id: 0000-0002-3622-4247
2019 (engelsk)Inngår i: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 50A, nr 8, s. 3842-3854Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Severe hot tearing has been observed during DC casting of modified AA3000 alloys with additions of Cu, Ti, and Zr, although these alloys are regarded as rather easy to cast. Extensive studies have been performed on both synthetic and industrial AA2000, AA6000, and AA7000 alloys, but less data are available for AA3000 alloys. This work was thus initiated to investigate the hot tearing susceptibility of AA3000 alloys with varying alloy element content using constrained rod casting molds. The results showed that the Cu and Fe content have a major impact on hot tearing resistance, while the effects of Zr and Ti are minor. Cu in a range from 0.3 to 1.2 wt pct significantly increased the hot tearing tendency. This is due to the existence of high eutectic fractions at low temperatures, as well as porosity formation associated with bad feeding at the end of solidification. A strong cracking tendency was observed below an Fe content 0.2 wt pct owing to decreased precipitation of the Al6(Mn, Fe) phase. It was found that primary Al6(Mn, Fe) phases lead to early bridging between the grains, which reinforces the alloy during the vulnerable temperature range for hot tearing. Zr and Ti additions weakly enhanced or reduced hot tearing severity, respectively.

sted, utgiver, år, opplag, sider
2019. Vol. 50A, nr 8, s. 3842-3854
HSV kategori
Identifikatorer
URN: urn:nbn:se:miun:diva-35940DOI: 10.1007/s11661-019-05290-1ISI: 000473514600040Scopus ID: 2-s2.0-85066900902OAI: oai:DiVA.org:miun-35940DiVA, id: diva2:1302224
Tilgjengelig fra: 2019-04-04 Laget: 2019-04-04 Sist oppdatert: 2019-10-16bibliografisk kontrollert
Inngår i avhandling
1. Problems in the Aluminium DC Casting Process Associated with Melt Treatment Operations
Åpne denne publikasjonen i ny fane eller vindu >>Problems in the Aluminium DC Casting Process Associated with Melt Treatment Operations
2019 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig) [Kunstnerisk arbeiden]
Abstract [en]

The quality of DC cast Al alloys is highly dependent on melt batch composition and impurity level in the molten alloy. The chemical composition and cleanliness of a melt is controlled through the melt treatment operations, carried out while the melt is still in the furnace before casting starts. The present work has studied some of these operations and associated problems such as slow dissolution of alloying elements, non-reproducibility in chemical composition analysis and inclusions.

 The results of the dissolution of the alloy elements Mn and Fe showed different behaviors.  For Mn three intermediate phases were involved, all of which exhibited a smooth interface between Mn and the liquid. These three phases were identified as the γ2, Al11Mn4, and µ phases, which grow slowly towards the dissolving Mn particles. The results from the Fe dissolution revealed that only one phase dominates the process, Al5Fe2, which penetrates the Fe particles with an irregular interface.

The interaction between Mn and Ti additions to AA3003 alloys and consequences for the solidification and precipitation behavior was investigated. The study could map the limits for formation of an earlier unknown AlMnTi phase, which formed large particles, detrimental for subsequent rolling operations.

Different sampling procedures for chemical composition analysis were studied, and a novel approach was proposed. A mould with an insulated periphery provided one-dimensional solidification, which gave compositions close to nominal.

 Inclusion distributions along as-cast billets were studied as a function of different holding times, and thus different grades of sedimentation. Holding times longer than 30 minutes did not show any improvements.  It was also shown that if melt remaining in the furnace at end of casting is less than about 3000 kg, the sedimented inclusions are stirred into the bulk again, and can enter into the end of the billet.

The impact on hot tearing susceptibility of different Cu and Fe contents for AA3000 alloys was studied. Cu contents in a range from 0.3 to 1.2 wt%  significantly increase the hot tearing tendency, which was attributed to bad feeding at end of solidification. Decreasing of the Fe content below 0.2 wt%, gives a strong cracking tendency, owing to decreased precipitations of the Al6(Mn,Fe) phase, which contributes to early bridging and thus reinforcement between grains.

sted, utgiver, år, opplag, sider
Sundsvall: Mid Sweden University, 2019. s. 67
Serie
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 294
HSV kategori
Identifikatorer
urn:nbn:se:miun:diva-35937 (URN)978-91-88527-89-9 (ISBN)
Disputas
2019-04-25, M102, Holmgatan 10, Sundsvall, 13:00 (engelsk)
Opponent
Veileder
Merknad

Vid tidpunkten för disputationen var följande delarbeten opublicerade: delarbete 6 (inskickat).

At the time of the doctoral defence the following papers were unpublished: paper 6 (submitted).

Tilgjengelig fra: 2019-04-04 Laget: 2019-04-03 Sist oppdatert: 2019-04-04bibliografisk kontrollert

Open Access i DiVA

fulltext(4086 kB)131 nedlastinger
Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 4086 kBChecksum SHA-512
67ea118d793206f6d6b98ed270566dc785d7632ca2abbb41ae1a08724db9ea2dbeb870d19e5e9d61810f796b7804b36ca39b379e51cd58e6d185991da061e591
Type fulltextMimetype application/pdf

Andre lenker

Forlagets fulltekstScopus

Personposter BETA

Razaz, GhadirCarlberg, Torbjörn

Søk i DiVA

Av forfatter/redaktør
Razaz, GhadirCarlberg, Torbjörn
Av organisasjonen
I samme tidsskrift
Metallurgical and Materials Transactions. A

Søk utenfor DiVA

GoogleGoogle Scholar
Totalt: 131 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 219 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf