CAJ | 학술논문

对2024铝合金进行不同温度下的热处理,得到了一系列具有不同溶质原子浓度的基体及析出相含量的铝合金试样.将这些试样分别在低温(-100℃)和室温(25℃)下进行拉伸实验,分析其锯齿幅值和临界应变随应变率的变化趋势.结果表明,溶质原子是Portevin-Le Chatelier(PLC)效应的必要因素,单纯的位错切割沉淀相不足以产生PLC效应,只能影响PLC效应,并且沉淀相对PLC效应的影响在中等拉伸应变率时表现明显.
대2024려합금진행불동온도하적열처리,득도료일계렬구유불동용질원자농도적기체급석출상함량적려합금시양.장저사시양분별재저온(-100℃)화실온(25℃)하진행랍신실험,분석기거치폭치화림계응변수응변솔적변화추세.결과표명,용질원자시Portevin-Le Chatelier(PLC)효응적필요인소,단순적위착절할침정상불족이산생PLC효응,지능영향PLC효응,병차침정상대PLC효응적영향재중등랍신응변솔시표현명현.
It is normally accepted that the interaction among solute atoms.dislocations and precipitate leads to Portevin-Le Chatelier(PLC) effect during the plastic deformation of alloys.Precipitate iS directly responsible for some inverse behavior of PLC effect.such as the inversion of the temperature dependence of critical strain;because these behaviors appear only when precipitate exist in the alloys.In this paper,the solute concentration iU matrix and the fraction of the precipitate in 2024 Al alloy are changed by heat treatment.Subsequently,tensile experiments are conducted at room temperature(25℃)and loW temperature(-100℃)on these treated specimens.The magnitude of serration and the critical strain of the serrated flow are analyzed and the results show that the diffusing solute atoms are necessary for the appearance of PLC effect while the cutting of the precipitate particles alone can not lead to this phenomenon.The mobile dislocations will be blocked and piled up strongly in the front of precipitate and thus precipitate will have an influence Oil PLC effect.This influence is obvious during tensile tests at medium strain rate.