High Temperature Creep Properties of Al-Al4C3-Al2O3 Alloy by Mechanical Alloying

摘要: Tensile tests and creep were carried out at high temperatures on an Al-Al4C3 alloy prepared by mechanical alloying technique. The material contains about 2.0 % carbon 0.9 oxygen in mass percent, the volume fractions of Al4C3 Al2O3 particles are estimated 7.4 1.4 %, respectively, from chemical composition. Minimum rate decreased steeply near two critical stresses, σcl (the lower stress) σcu upper stress), with decreasing applied stress below 723 K. Instantaneous plastic strain was observed above a stress, σci, each test temperature. σci fairly close to 0.2% proof obtained tensile It is thought that correspond microscopic yield macroscopic respectively. corresponds local needed for dislocations move soft region within subgrains. low range K arises mainly deformation region. equivalent necessary subgrains or subboundaries; this can extensively beyond subboundaries under point deformation. At higher 773 K, influence diffusional increases exponent decreases.