An investigation of shear deformation in a semi-solid state of a high strain rate superplastic Si{sub 3}N{sub 4p}/Al-Mg-Si composite

Journal Article · Fri Sep 18 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00223-7· OSTI ID:665189

Mabuchi, M ^[1]; Iwasaki, H ^[2]; Higashi, K ^[3]

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1. National Industrial Research Inst., Nagoya (Japan)
2. Himeji Inst. of Tech., Shosha, Hyogo (Japan)
3. Osaka Prefecture Univ., Sakai, Osaka (Japan)

Shear deformation behavior in a wide temperature range of 683--893 K and at 2 {times} 10{sup {minus}3}{minus}3/s for a high strain rate superplastic Si{sub 3}N{sub 4p}/Al-Mg-Si composite is described. The dominant deformation mechanism was dislocation creep at 683--773 K, superplasticity containing no liquid phase at 813--823 K, superplasticity containing a liquid phase at 833--863 K and deformation related to the liquid flow at 873--893 K, respectively. In the superplasticity region, the shear strain to failure was significantly increased by the presence of a discontinuous liquid phase. At 873--893 K, high m of about 1 was attained. The deformation in this temperature range is likely to be the lubricated flow in a semi-solid state containing a continuous liquid phase. However, ductility was low in this region. This is probably because of decohesion at boundaries with a thick liquid phase.

• OSTI ID: 665189
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 15 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COMPOSITE MATERIALS
DEFORMATION
LIQUID METALS
MAGNESIUM ALLOYS
PLASTICITY
SILICON ALLOYS
SILICON NITRIDES
STRAIN RATE
TEMPERATURE DEPENDENCE