Mehanske lastnosti
Brass has different mechanical properties due to different zinc content. Fig. 7 is a graph showing the change of mechanical properties of brass with different zinc content. For brass, σb and δ increase with the increase of zinc content. For ( plus ) brass, the strength at room temperature increases continuously before the zinc content increases to about 45 percent . If the zinc content is further increased, the R phase with greater brittleness (solid solution based on Cu5Zn8 compound) appears in the alloy structure, and the strength decreases sharply. The room temperature plasticity of ( plus ) brass always decreases with the increase of zinc content. Therefore, the copper-zinc alloy containing more than 45 percent zinc has no practical value.
Navadna medenina se pogosto uporablja, kot so jermen rezervoarja za vodo, cev za oskrbo z vodo in drenažo, medalja, valovita cev, serpentinska cev, kondenzatorska cev, ohišje, različni kompleksni luknjani izdelki, strojna oprema in tako naprej. S povečanjem vsebnosti cinka iz H63 na H59 lahko dobro prenesejo vročo obdelavo in se večinoma uporabljajo v različnih delih strojev in električnih naprav, delov za žigosanje in glasbil.
Za izboljšanje odpornosti proti koroziji, trdnosti, trdote in obdelovalnosti medenine je potrebna majhna količina elementov, kot so kositer, aluminij, mangan, železo, silicij, nikelj, svinec itd. (na splošno 1 odstotek 2 odstotka, nekaj do 3 odstotke 4 odstotke in nekaj do 5 odstotkov) se dodajo bakrovi-cinkovi zlitini, da tvorijo ternarne, kvartarne ali celo kvinarne zlitine, kar je zapleteno
Koeficient cinkovega ekvivalenta
The microstructure of complex brass can be calculated according to the "zinc equivalent coefficient" of elements added in brass. Because a small amount of other alloying elements are added to Cu-Zn alloy, the /( plus ) phase region in Cu-Zn state diagram usually moves to the left or right. Therefore, the microstructure of special brass is usually equivalent to that of ordinary brass with increased or decreased zinc content. For example, the microstructure of Cu-Zn alloy with 1 percent silicon is equivalent to the alloy structure with 10 percent zinc added in Cu-Zn alloy. So the "zinc equivalent" of silicon is 10. The "zinc equivalent coefficient" of silicon is the largest, which makes the /( plus ) phase boundary in Cu-Zn system significantly move to the copper side, that is, the phase region is strongly reduced. The "zinc equivalent coefficient" of nickel is negative, that is, the phase region is enlarged.
-faza in -faza v posebni medenini sta kompleksni večelementni trdni raztopini, ki imata velik učinek krepitve, medtem ko -faza in -faza v navadni medenini so preproste trdne raztopine Cu-Zn, ki imajo nizek ojačitveni učinek. Čeprav je cinkov ekvivalent enak, so lastnosti večkomponentne trdne raztopine in enostavne binarne trdne raztopine različne. Zato je majhna količina večelementne ojačitve{6}} način za izboljšanje lastnosti zlitine.
