H59 Brass Material in cnc prototyping and production

Basic introduction

H59 brass is the cheapestBrass, has high strength and hardness and good plasticity, and can still withstand pressure processing well in hot stateCorrosion resistanceGeneral, other properties andH62Approximate.

Mechanical properties

Tensile strengthσb (MPa):≥294

Elongationδ10 (%):≥25

Note: Tensile mechanical properties of sheet

Sample size: thickness 0.5～15

(1) OrdinaryBrass "Room temperature structure". 

Ordinary brass is a copper-zinc binary alloy, and its zinc content varies greatly, so its room temperature structure is also very different. According to Cu－Zn binaryStatus diagram, There are three types of room temperature structures of brass: brass Material in cnc prototyping and production with a zinc content of less than 35%. The microstructure at room temperature is composed of a single-phase α solid solution, called α brass; the zinc content is within the range of 36%～46%. Brass, the microstructure at room temperature is composed of two phases (α+β), called (α+β) brass (two-phase brass); Brass containing more than 46% ～50% zinc, at room temperatureMicrostructureConsists of only the beta phase, known as betaBrass。

(2)PressureworkingPerformance

Alpha single phase brass (from H96 to H65) has good plasticity and can withstand cold and heatProcessingBut α single-phase brass is forging, etcHot-workingMedium-temperature brittleness is prone to occur, and its specific temperature range changes with different Zn contents, generally between 200～700℃. Therefore, the temperature should be higher than 700℃ during hot processing. The main reason for the formation of the medium-temperature brittle zone of single-phase α brass is the presence of two ordered compounds, Cu3Zn and Cu9Zn, in the α-phase zone of the Cu-Zn alloy system. They undergo an orderly transformation during medium and low temperature heating, making the alloy brittle; in addition, there are trace amounts of lead and bismuth harmful impurities in the alloy formed with copperLow melting pointEutecticThe films are distributed over grain boundaries, producing intergranular rupture during hot working. Practice has shown that the addition of trace amounts of cerium effectively eliminates mesothermal brittleness.

Two-phase brass (from H63 toH59), in addition to the alpha phase with good plasticity in the alloy structure, there is also aElectron compoundsCuZn-based beta solid solution. The beta phase has high plasticity at high temperatures, while the beta' phase at low temperatures (Ordered solid solution)Hard and brittle in nature. Therefore (α+β)BrassForging shall be carried out in a hot state. Beta brass with a zinc content greater than 46%～50% cannot be subjected to pressure processing due to its hard and brittle properties.

(3) Mechanical properties 

The mechanical properties of brass are also different due to different zinc contents. For alpha brass, both sigma b and delta increase as the zinc content increases. For (α+β) brass, room temperature strength increases continuously before zinc content increases to about 45%. If the zinc content is further increased, the strength decreases sharply due to the appearance of a more brittle r-phase (a solid solution based on the Cu5 Zn8 compound) in the alloy structure. ( The room temperature plasticity of α+β) brass always decreases with the increase of zinc content. So the zinc content is more than 45%Copper-zinc alloyNo "practical value".

OrdinaryBrassThe uses are extremely wide, such as water tank belts, water supply and drainage pipes, medals, bellowsSerpentine、Condenser, cartridge cases and various complex-shaped punching products, small hardware, etc. As the zinc content increases from H63 toH59, They can withstand hot processing very well, mostly used in various parts of machinery and electrical appliancesStamping partsAnd "instruments, etc".

Heat treatment

Hot-workingTemperature 730～820℃

Annealing temperature600～670℃.