铜粉末注射成形工艺

Technology of copper powder injection molding

用<74μm的电解铜粉做原料探索铜粉末注射成形工艺,重点研究注射参数对生坯的影响及脱脂烧结过程中变形的控制。脱脂工艺为:2℃/min升温至160℃保温60 min,1℃/min升温至250℃保温90 min,2.5℃/min升温至400℃保温60 min,4℃/min升温至650℃保温60 min。烧结条件为:烧结温度950℃,烧结时间90 min。结果表明:注射坯的尺寸和质量均随注射温度的升高而下降,随注射压力和注射速度的增大而增大,注射参数的变化对注射坯密度影响不大;在脱脂烧结过程中,利用填料的支撑作用,能有效地控制产品变形。采用粉末注射成形新技术制备的铜制品,其性能为:密度8.34 g/cm3,抗拉强度σb=201 MPa,σ0.2=71.9 MPa,伸长率δ=27.5%。

For developing a new production technology, the copper powder injection molding using electrolytic copper powders with particle size less than 74μm was studied, and the influences of injection parameters to the green part and the deformation of the copper products in dehinding and sintering processes were systematically investigated. The results show that during injection the size and mass of the green part minish with the raising of the temperature of the feedstock and augments with the raising of the injection pressure or injection rate, and what is more different injection parameters didn＇t change the green part density much. The dehinding technology is as below; heat up to 160 ℃ in a rate of 2 ℃/min, and then hold on 60 min; heat up to 250 ℃ in 1 ℃/min, hold on 90 mini heat up to 400 ℃ in 2.5 ℃/min, hold on 60 min;heat up to 650 ℃ in 4 ℃/min, hold on 60 min. The sintering conditions are that sintering temperature is 950 ℃, sintering time is 90 min. The deformation can be controlled effectively by using a packing material to support the green part during debinding and sintering. The tensile properties of eopper sample produced by the above technology are density of 8.34 g/cm^3 , σb =201 MPa, σ0.3 =71.9 MPa, σ=27.5%.