High Temperature Fatigue Behavior of A356 and A319 Heat Resistant Aluminum Alloys

A356 및 A319 내열 알루미늄 합금의 고온 피로 변형 거동

  • 박종수 (안동대학교 공과대학 신소재공학부 청정소재기술연구센터) ;
  • 성시영 (자동차부품연구원 소재공정연구센터) ;
  • 한범석 (자동차부품연구원 소재공정연구센터) ;
  • 정창렬 (한국생산기술연구원 동력부품지원센터) ;
  • 이기안 (안동대학교 공과대학 신소재공학부 청정소재기술연구센터)
  • Published : 2009.10.08

Abstract

In this study, fatigue samples were prepared from cylinder head parts that are actually used in domestic (A) and foreign (B) automobiles; high-temperature, high-cycle, and low-cycle fatigue characteristics were then evaluated and compared. A study on the correlation between the microstructural factor and high temperature fatigue characteristic was attempted. The chemical compositions of the heat resistant aluminum alloys above represented A356 (A) and A319 (B), respectively. The result of the tensile strength test on material B at $250^{\circ}C$ was higher by 30.8MPa compared to material A. On the other hand, elongation was 8.5% higher for material A. At $130{\circ}C$, material B exhibited high fatigue life given high cycle fatigue under high stress, whereas material A showed high fatigue life when stress was lowered. With regard to the low-cycle fatigue result ($250^{\circ}C$) showing higher fatigue life as ductility is increased, material A demonstrated higher fatigue life. Through the observation of the differences in microstructure and the fatigue fracture surface, an attempt to explain the high-temperature fatigue deformation behavior of the materials was made.

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