| 摘要 |
FIELD: composite materials. SUBSTANCE: composite material contains copper shell and core fully embraced with shell and consisting of copper matrix with uniformly distributed metal oxide particles therein. Metal oxide is one or more of oxides selected from the group: aluminium, titanium, and hafnium oxides. Metal oxide content is 0.12-1.45 wt %, the balance being copper. Average size of oxides does not exceed 50 nm, and shell surface area constitutes at least 10% of material cross-section area. Aluminium oxide preferable content is 0.15-1.4 wt % (advantageously 0.19-1.2) and that of titanium and/or hafnium oxides 0.06-0.85 (0.1-0.8). If three oxides are present, their preferable content is to be 0.123-1.42 wt % (advantageously 0.85-1.08). In this case, Al/Hf/Ti oxide ratio should be (4-10):1:1 and their average size at most 10 nm. Method of manufacturing composite includes smelting copper-based alloy with at least one metal (Al, Ti or Hf) in amount not exceeding 0.8 wt %. Dispersing of alloy produces powder with average particle size up to 150 mcm and maximum size 315 mcm. Powder is then internally oxidized at 700-950 C in air for a period of time determined from formula: τ=KRΣ(γc)/6P, where K is coefficient depending on powder shape and equal to 1-3; R powder particle size (cm); γ- stoichiometric relation for i-th alloying element in the formula; catomic portion of i-th alloying element; P oxygen permeability in copper at oxidation temperature (atomic portion sq.cm/s). Thereafter, recovery annealing is performed followed by extruding powder in shell at 700-950 C with stretching rate at least 10 to form composite material. EFFECT: improved parameters of process. 18 cl, 1 dwg, 1 tbl |
