Yascheritsin E. The structure and mechanical properties of multi-layer copper-tantalum composites obtained by the diffusive-welding method

Investigation objects. The investigation object is working out technology receipt, optimization structure and mechanical properties of multi-layer on copper basis composites obtained by the diffusive-welding method. The aim and problem investigation. The aim thesis is working out technology regime receipt properties of multi-layer copper-tantalum composites with high mechanical and conduction properties obtained by the diffusive-welding method. For aim improvement was put uh and decisive next aim: metal choice intermediate layer receipt copper and intermediate layer; put regime diffusive-welding, provision safe adhesion bond between Cu and Ta; definition influence gas-saturate tantalum by making composites and relative layer depth diffusion between copper and nickel on strengthening characteristics Cu-Ta composites; investigation description peculiarity multi-layer copper-tantalum composites by stretching and influence on their plasticity structure and mechanical properties layer compiling; definition dependence mechanical, relaxation properties by stretching this composites from tantalum and quantity foilscopper layer in each copper layer with aim optimization at room and high temperature, control conduction properties. Investigation methods: optical and electronic microscopes for investigation structure layer compiling composites help microscopes МИМ-7 and РЭММА-101; x-ray and x- ray-fluorescentny method with help instrument УРС-60, ДРОН-3, СПРУТ-4; mechanical tests for properties definition composites Cu-Ta and components in stretching regimes with constant velocity and relaxation firmness by 20 and 6000С by help explosive machine original construction and TIRATEST-2200; measuring micro hardness foils, vacuum condensation Cu and foils Ta standard method on instrument ПМТ-3; control conduction properties method four point probe accompany comparators Р3009. Work novelty scientific. 1.Conformity to natural laws process deforming multilayer copper-tantalum composites with investigation temperature (20 and 6000С), concentration (1-25 % Та) and regime deforming( stretching and relaxation firmness) in dependence volume part Ta determine. Demonstration that mechanical properties non corresponding known's scheme characteristically for one-direction composite with plasticity matrix and fragile fibrous. 2. Determine that relative contraction matrix copper in zone description composites by 200С all investigation interval volume part Ta(1-25 % Та) non change and in two timeless by comparison matrix in freedom state, from with this significance composition 80%. Interpretation this effect on basis difference thermo-elastic properties components composites suggest. 3. On the 7-11,1 % tantalum range the intermediate stretching diagrams type that does not correspond to two traditional diagram types for multilayer composites with plastic matrix and fragile fibre has been found. 4. It is determined that at the high temperatures in the 11,1- 15,8 % tantalum rang the increased rates of strengthening characteristics growth are due to the decreasing effect of grain-boundary sliding in the transition to the cellular structure in the copper matrix. 5. Unmonotonous behavior in concentration dependence of relaxation firmness of the composites understudy at the 6000С in the 0-25 % tantalum range has been first set. Practical significance received results.1. The new and more cheap method of preparing multilayer Cu-Ta composites is suggested and technological regime (welding time, pressure on layer by welding, vacuum degree) diffusive welding method through the Ni-foil layer is elaborated. Complex research of the structure, mechanical and current conduction properties of these composites in the concentration range from 1 to 25 % of volume Ta parts carried out by 20 and 6000С. 2. It has been found that 2,8 ? 7 % tantalum composites have optimal mechanical and conduction properties at room and high temperature. Bring recommendation may be use by production current conduction and heat conduction construction materials, heat- solider construction element, heat conduction coat surface press-form for production plasmas wares. That is why, suggestion use Cu-Ta composites as material tyre-wires, that was approbation in CLR " Inios" and quality current- and heat conduction coat surface press-form in OJSC "Salut" t. Kharkov. In particular, term use press-form by this increase in 1,65 time. Field use: electro-technical and radio- technical industrial