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摘要：产品微型化已经成为产业界的趋势之一，而微型弹簧作为重要结构件，需求量也随之急剧增长。本文自主设计了微挤压式模具并成功制备出长度8 mm，宽度2 mm的QAl7铜合金弹簧柱，经切割后可以获得微型弹簧。研究表明：润滑条件、挤压速度适当的升高、退火处理均可使挤压力有明显的下降，也可提高微弹簧表面质量和尺寸精度；微弹簧边缘区域的晶粒尺寸明显小于中心区域，晶粒得到明显细化；微弹簧的显微硬度呈现两端低，中间位置高的分布。与有润滑相比，无润滑条件下微弹簧各部分的显微硬度均有所增加。另外，挤压速度越高，挤压件的硬度也越高。23352
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关键词： 微弹簧，QAl7铜合金，微挤压
毕业设计说明书（毕业论文）外文摘要
Title Study on preparation of high strength copper alloy micro-spring
Abstract
Product miniaturization has become one of the trends in the manufacturing industry and micro springs are one of important structural accessories. The demand for micro-spring has grown sharply. In this thesis，the manufacturing process of the spring is presented and its characteristics are also analyzed. First，a micro extrusion die was designed and manufactured. Second，a crude spring of QAl7 copper alloy with 8 mm of length，2 mm of width was manufactured by cold extrusion. The required micro spring was created after cutting the crude spring. The experiments have showed some significant conclusions. Using lubrication，increasing extrusion speed，annealing not only could make the extrusion pressure reduce markedly; but also improve the spring surface quality and dimensional accuracy. Grain size on the edges of the spring was much smaller than that on the center of the spring. The micro-hardness of the spring gets small values at the ends and gets higher values at the middle. Additionally，the micro-hardness is higher without lubrication and proportionally increases with extrusion speed.
Key words： Micro-spring，QAl7 copper alloy， Micro-extrusion
目 次
1 绪论 1
1.1 引言 1
1.2 微成形简介 1
1.2.1 微成形技术 1
1.2.2 微成形技术的特点及应用 1
1.2.3 现阶段微成形技术领域 2
1.2.4 目前研究面临的技术问题 2
1.3 微挤压技术的发展现状 3
1.4 微型弹簧的发展现状 5
1.5 铝青铜基本特性与在微弹簧设计中的优势 8
1.6 本文研究意义与主要内容 9
1.6.1 本文研究意义 9
1.6.2 本文研究内容 9
2 实验材料及方法 11
2.1 实验原料 11
2.2 坯料预处理实验 11
2.2.1 退火处理工艺 12
2.2.2 试样线切割 13
2.2.3 预磨坯料 14
2.3 微成形及测试设备 14
2.4 微弹簧模具 14
2.5 微挤压实验方案 17
2.6 实验分析方法 17
2.6.1 外观形貌观察 17
2.6.2 金相样品制备与微观组织的观察 17
2.6.3 硬度测试试验 17
3 QAl7铜合金微弹簧挤压成形性能研究 18
3.1微成形挤压力-位移曲线分析 18
3.1.1 摩擦条件对挤压力的影响 19
3.1.2 挤压速度对挤压力的影响 19
3.1.3 晶粒尺寸对挤压力的影响 20
3.2 微弹簧的成形质量分析 21
3.2.1 摩擦条件对成形质量的影响 22