Cost-Effective Production of CuCrZr Alloy Using Powder Metallurgy

Abstract

Legura CuCrZr predstavlja aktuelan materijal sa potencijalnom primenom kao konstrukcioni materijal u budućim fuzionim reaktorima. Cilj ovog istraživanja je da se proizvede poboljšana CuCrZr legura primenom metalurgije praha (PM). Korišćene su PM tehnike mehaničko legiranje, hladno presovanje i sinterovanje. Komercijalno proizvedeni predlegirani CuCrZr prahovi su mehanički legirani 5 sati u inertnoj atmosferi argona korišćenjem visokoenergetskog mlina (Turbula mikser) sa kuglama različitih veličina. Mehaničkim legiranjem (ML) postignuto je povećanje gustine dislokacija matrice bakra, što dovodi do povećanja tvrdoće nakon densifikacije. Strukturni parametri (veličina kristalita, naprezanje i parametri rešetke) ML prahova i kompakta su ispitivani pomoću rendgenske difrakcije. Dobijeni rezultati pokazuju smanjenje veličine kristalita i parametra rešetke Cu matrice nakon ML. Dalje, XRD analiza je potvrdila prisustvo CuZr ojačavajućih čestica nakon sinterovanja. Mikrostrukturna analiza i distribucija ojačavajućih čestica Cu matrice izvršena je primenom SEM i XRD. Merenja tvrdoće su pokazala da in situ formiranje CuZr unutar Cu matrice povećava vrednosti tvrdoće za 45% u poređenju sa vrednostima tvrdoće čistog bakra.

Promising copper-based material with potential application in future fusion reactors, as construction material, is CuCrZr alloy. The aim of this study was to produce improved CuCrZr alloy using powder metallurgy (PM). Applied PM techniques were mechanical alloying, cold pressing and sintering. The commercially produced prealloyed CuCrZr powders was mechanically alloyed (MA) for 5 hours in argon inert atmosphere using high-energy ball mill (Turbula mixer). Mechanical alloying was employed to increase dislocation density inside the Cu matrix which will contribute hardness enhancement after densification. Structural parameters (crystallite size, strain and lattice parameters) of MA powders and compacts were investigated using X-ray diffraction. Obtained results indicate that after mechanical alloying, crystallite size and lattice parameters of copper matrix decrease compared to starting material. Further, XRD analysis confirmed presence of CuZr reinforcing particles after sintering. Microstructural analysis and distribution of reinforcing particles inside the Cu matrix were performed using SEM and XRD. Measurements of hardness showed that in situ formation of CuZr inside the Cu matrix significantly raise hardness values 45% compared to hardness of pure copper compact.