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本文研究了高合金化的 Al—Cu—Zn 无磁合金经过均匀化退火。淬火及时效处理后,其组织和性能的变化,作为该合金热处理的依据。试验结果表明,含18—20%Cu 及20—22%Zn 的铸造 Al 合金铸态下的 H_B 值约为105kgf/mm~2,均匀化退火后减小到84kgf/mm~2。经过440℃淬火和自然时效后,其硬度随时效时间而增大,20天后 H_B 值由淬火状态的104kgf/mm~2增加到123kgf/mm~2;440℃淬火和160℃人工时效后,合金的硬度明显减小,时效29小时后,H_B 值约为76kgf/mm~2。淬火后自然时效或者淬火后人工时效,该合金的碎化率不发生明显的变化,测得的 K 值为0.08～0.09×10~(-6)cm~3/g,而铸态下的磁化率比这个数值要小(0.04～0.06×10~(-6)cm~3/g)均匀化状态的 k 值略低于铸态。上述性能是由各种状态下合金中的组织特征决定的。均匀化退火后,合金的组织为α+T′+η;淬火后,保留了高温α+CuAl_2的组织特征,再经人工时效后,η自两个相中析出,η为非强化相,因而,该合金用淬火时效不能达到强化的目的,不宜采用此种热处理形式。
In this paper, the high alloyed Al-Cu-Zn non-magnetic alloys were homogenized and annealed. Quenching and aging treatment, the organization and performance changes, as the basis for the alloy heat treatment. The experimental results show that the H_B value of as-cast Al alloy containing 18-20% Cu and 20-22% Zn is about 105kgf / mm ~ 2 after as-cast casting and decreases to 84kgf / mm ~ 2 after homogenization annealing. After quenching at 440 ℃ and natural aging, the hardness increases with the aging time. After 20 days, the H_B value increases from 104kgf / mm ~ 2 to 123kgf / mm ~ 2 after quenching; after quenching at 440 ℃ and artificial aging at 160 ℃, The hardness decreases obviously, after 29 hours aging, H_B value is about 76kgf / mm ~ 2. After quenching, natural aging or artificial aging after quenching, the alloy has no obvious change in the rate of disintegration, and the measured K value is 0.08-0.09 × 10 -6 cm -3 / g, while the magnetization under the as-cast condition The rate of homogenization was slightly lower than that of as-cast (0.04-0.06 × 10 -6 cm -3 / g). The above properties are determined by the microstructure characteristics of the alloy in various states. After homogenization annealing, the microstructure of the alloy is α + T ’+ η. After quenching, the microstructure of high-temperature α + CuAl_2 remains. After artificial aging, η precipitates from both phases and η is a non-strengthening phase , The alloy quenching aging can not achieve the purpose of strengthening, should not be used in this form of heat treatment.