Trends in the Development of Machinery and Associated Technology ” TMT 2010 , Mediterranean Cruise , 11-18 September 2010 ANNEAL HARDENING EFFECT IN SINTERED COPPER ALLOYS DEPENDENCE ON ALLOYING ELEMENTS AND DEFORMATION
This paper reports results of investigation carried out on sintered copper alloys: Cu-8at%Ni, Cu8at %Zn, Cu-8at%Al, Cu-8at%Ag, Cu-4at%Ni-4at%Sn, Cu-4at%Ni-4at%Zn and Cu-4at%Au. For comparison, investigation carried out on the sintered copper. The sintered alloys, as well as pure copper, were subjected to the same thermomechanical treatment. Thermomechanical treatment included cold rolling of 30,50 and 70% in reduction. Isochronal and isothermal annealing up to the recrystallization temperature were performed, followed with hardness and electrical conductivity measuring. This investigation shows that hardness and electrical conductivity of cold deformed copper-alloys increase after annealing in the temperature range of 160 400°C, due to anneal hardening effect. Electrical conductivity decreases with increasing the amount of alloying elements. During the annealing the electrical conductivity slowly increases for both set of the samples copper and alloys due to recovery and recrystallization
Anneal hardening effect in sintered copper alloys
Samples of copper and copper alloys CuNi and CuNiAl were prepared by a powder metallurgical method and were then subjected to cold rolling with different degrees of deformation. Copper and copper alloys in the cold-rolled state were isochronally annealed up to the recrystallization temperature during which hardness and electrical conductivity were measured. This investigation shows that the anneal hardening effect occurs in a temperature range of 450 - 650 K, followed with an increase in hardness of alloys.
Modeling the effect of recovery on the room temperature fracture strength of W-0.01% K (non-sag) wire
The room temperature (RT) strength and ductility of potassium doped tungsten wire (i.e. non-sag) varies significantly with annealing conditions. Wire, in an as-drawn condition, exhibits limited ductility ( 1,100 C) of drawn, doped tungsten wire. The result is of interest to those who specify doped tungsten wire for applications where strength retention, after thermal processing (i.e. brazing, annealing, metal-matrix/metal-fiber composites), is important.