Characteristics of Plasticity of Hot Deformed Cu-Ti Alloys/ Charakterystyki Plastyczności Odkształcanych Na Gorąco Stopów Cu-Ti

Abstract

In the paper, results of a study on the effects of deformation conditions (temperature, strain and strain rate) on flow curves, maximum flow stress and corresponding deformation of Cu-Ti alloys with various Ti contents, subjected to hot deformation, are presented. Evaluation of formability of alloys was performed with the use of a Gleeble HDS-V40 thermal-mechanical simulator during uniaxial hot compression at 700 to 900• C, strain rate of 0.1 to 10.0 s −1 and strain of 0 to 1.2 (70%). It was found that within the analysed ranges of temperature, strain rate and strain, Cu-Ti alloys underwent uniform deformation without cracking. The largest deformation resistances were observed for the alloys with the highest Ti contents; their decrease was possible with the temperature raise and the strain rate reduction.Keywords: copper-titanium alloy, hot compression test, plasticity, flow curves W pracy przedstawiono wyniki badań wpływu warunków odkształcenia (temperatura, wielkość i prędkość odkształcenia) na przebieg krzywych płynięcia, wartość maksymalnego naprężenia uplastyczniającego i odpowiadającego mu odkształcenia odkształcanych plastycznie na gorąco stopów Cu-Ti o zróżnicowanej zawartości Ti. Ocenę podatności do kształtowania plastycznego stopów przeprowadzono na symulatorze cieplno-mechanicznym systemu Gleeble HDS-V40 w warunkach jednoosiowego ściskania na gorąco w zakresie temperatury od 700 do 900• C, prędkości odkształcenia od 0.1 do 10.0 s −1 i odkształcenia od 0 do 1.2 (70%). Stwierdzono, że w analizowanych przedziałach temperatury, prędkości i wielkości odkształcenia stopy Cu-Ti odkształcają się w sposób jednorodny bez udziału pękania. Wykazano, że największe opory kształtowania plastycznego towarzyszą stopom o najwyższej zawartości Ti, a ich zmniejszenie jest możliwe poprzez podwyższenie temperatury i obniżenie prędkości odkształcenia.

Microstructure of Hot-Deformed Cu-3Ti Alloy

“…In this case, when the maximum flow stress is reached, further alloy deformation occurs with practically unchanged stress, which proves that under these conditions, the effect of hardening due to deformation and softening due to the structure rebuilding, resulting from recovery and/ or dynamic recrystallization, are in balance. Similar flow curves were recorded during compression at the strain rates of 0.1 and 1.0 s -1 [12]. The Cu-3Ti alloy subjected to hot deformation demonstrates homogeneous, equiaxial grain microstructure (the average grain diameter: 72.3 µm) with numerous large precipitates at the grain boundaries and considerably smaller ones inside (Fig.…”

“…solution heat treatment and aging, intended to ensure a required hardening level [3,7,11,12,21]. Sometimes, to obtain a higher hardening effect, the cold working process is performed between the solution heat treatment and aging processes [10,22,23].…”

“…Due to their toxicity, the use of beryllium bronzes has been forbidden for many years in Poland and EU countries as beryllium compounds are hazardous during melting, casting, pressure welding, welding, hot deformation, cutting and grinding [1,13]. For many years, therefore, worldwide studies have been focused on discovering cheaper and non-toxic substitutes for Cu-Be alloys [1][2][3][4][5][6][7][8][9][10][11][12]14]. Currently, the best substitutes for beryllium bronzes seem to be binary Cu-Ti or multicomponent CuTi-X alloys that demonstrate mechanical properties and conductivity comparable to those of beryllium bronzes [15][16][17].…”

“…Beryllium bronzes are commonly used when sparking causes explosion hazard and for applications where good strength and conductivity as well as abrasion resistance, elasticity and corrosion resistance are required [1][2][3][4][5][6][7][8][9][10][11][12].…”

Archives of Metallurgy and Materials

“…Dilute Cu-Ti alloys (containing approximately 1%-5% (mass fraction) Ti) are widely known since the 1930s as a substitute for expensive and toxic Cu-Be alloys [1]. They can be applied for the production of high-strength springs as well as elements resistant to corrosion and abrasion, as electronic components, electrical connections, contacts, relays, electrical wires, gears, and as components of equipment for anti-terrorist and mining rescue units compared to those of Cu-Be [2]. The equilibrium phase in the Cu-Ti system is usually formed by classical Widmanstatten or cellular precipitation.…”