CC5083冷轧板电阻炉快速加热再结晶退火得等轴晶

Gain Equiaxed Gains through Rapid Heating in Resistance Furnace for Cold-Rolled Cc5083 Aluminum Alloy

CC5083铝合金冷轧板经过电阻炉常规再结晶退火后组织晶粒粗长而影响性能。采用发明工艺电阻炉到温入炉快速加热1 h再结晶退火试样,经偏光金相观察获得的组织晶粒呈等轴、细小,此等轴、细小晶粒组织对性能有利;利用电子背散射技术观察再结晶晶界及晶内分布细小、弥散第二相,经X-射线衍射检测第二相为Mg5Al8。获得等轴、细小再结晶晶粒的机理是到温入炉快速加热再结晶退火时形核率高,再结晶晶界上弥散分布的细小第二相Mg5Al8颗粒阻止再结晶晶粒长大;铝合金基体中保持细小弥散的第二相有利于获得等轴细小再结晶晶粒。电阻炉到温入炉快速加热再结晶退火工艺适于CC5083铝合金冷轧板工业应用。

The grain shape of CC5083 aluminium alloy cold rolled plate is long and large after conventional re-crystallization annealing in resistance furnace and has bad performance.After the samples are re-crystallized annealing(use the invention processes),namely,when the temperature of furnace is up to the recrystallization temperature of the samples,the samples are put into resistance furnace and the temperature of furnace was quickly up to the recrystallization temperature of samples and held 1 h.Polarization metallographic microscopy showed that the grain size of the sample was equiaxed and fine.Fine dispersed precipitated phase particles were observed in the basal phase grain bound-aries under EBSD and the precipitation phase was Mg5Al8 according to the XRD.The mechanism of fine equiaxial grains gained is that:the recrystallization nucleation rate is high when the furnace is rapidly heated to the recrystallization temperature of the samples,and the samples are put into furnace and the temperature of furnace is quick to recrystallization temperature and holds for an-nealing.The fine second phase Mg5Al8 particles dispersed on the recrystallized grain boundaries prevent recrystallized grain growth;maintaining a finely dispersed second phase in the aluminum alloy matrix is advantageous for obtaining equiaxed fine recrystallized grains.The annealing pro-cess is suitable for industrial application of CC5083 aluminum alloy cold rolled sheet.