【摘要】 应用雾化方法制备了Cu-0.5Cr、Cu-0.8Cr和Cu-1.5Cr的3种预合金粉末,经压制成型后对其进行时效处理。测量了时效后样品的显微硬度,并对经200℃×480 m in时效后的Cu-0.5Cr合金压坯进行了背散射电子分析。结果表明,经大量变形后,合金在时效过程中产生了较为复杂的变化。在200℃时效初期,回复过程占主导地位,合金硬度有所下降;之后析出占主导地位,合金硬度又有所上升;而在500℃时效时,Cr的析出强烈推迟了再结晶的发生。结果还表明,Cr从Cu基体中的析出规律为先通过扩散在合金中的缺陷较高的部位形成富集区,再形核长大。更多还原

【Abstract】 The pre-powders of Cu-0.5Cr,Cu-0.8Cr,Cu-1.5Cr were produced by atomizing process,and the ageing treatment was carried out after compacting.The microhardness of the samples after ageing was measured,as well as the BSE images of Cu-0.5Cr alloy compact aged at 200 ℃ for 480 min.The results show that intricate transformation happens during ageing process after deep deformation.At the beginning of ageing at 200 ℃,reversion process plays dominant role,and the microhardness of alloys decreases slightly,then precipitation become dominant and the microhardness of alloys shows certain increase.While ageing at 500 ℃,recrystallization process is delayed by Cr precipitations.The results also show that the precipitation process of Cr from Cu matrix is first forming Cr-rich zone at the place with high crystal defects through diffusion then nucleating and growing up.更多还原