隨著電子零件在微彈簧、微馬達的軸心、微扣件零件與微泵浦的需求大增，加速了微成型加工技術的開發急迫性。然而，當縮小尺寸時，材料的流動變得不均勻且製程也不能預測，微成型中出現的尺寸效應，並不能用傳統的塑性理論直接用於微零件的模擬上，而加熱成型是降低微成型中尺寸效應的最有效處理方法，但是微成型的加工應用幾乎以微引伸、微沖頭為主，但無微齒輪的開發，而齒輪的應用極廣，故本研究以微齒輪的成形技術開發為主軸，所設計的齒型以微漸開線正齒輪、微斜齒輪與微雙階正齒輪為標的，並使用鈦合金作為加熱擠壓的材料進行微齒輪的擠壓。
對試棒進行不同的晶粒尺寸均質化熱處理，在熱拉伸試驗中以不同的拉伸速度來獲得不同晶粒尺寸的機械性質，並將數據帶入Deform 2D/3D有限元素分析進行微正齒輪、微斜齒輪與微雙階正齒輪的熱擠壓成型分析。以微正齒輪以400℃的熱擠壓進行0.5、1與10mm/s的擠壓速度找出合適的加工參數，發現0.5與1mm/s能對微正齒輪模具進行材料的充填，而10mm/s卻無法有效的充填，能確定加熱擠壓要使用慢速。根據模具的耐熱程度，模具溫度不能超過600℃否則會有降低強度的可能，故微正齒輪擠壓溫度以500℃與擠壓速度0.5mm/s進行實驗，在實驗的結果齒型內的晶粒尺寸在齒根圓區域皆細化且強度高於初始的硬度，充填率達到99%。微斜齒輪的模擬以400~600℃進行熱擠壓且速度以0.5mm/s，在400℃擠壓能將模具充滿。實驗結果在齒根圓區域出現晶粒細化，內部結構皆是細小晶粒且強度值是初始值約2倍，不同晶粒尺寸的齒輪充填率也可以達到99%，代表溫度能影響到晶粒尺寸的充填行為。微雙階齒輪的擠壓方式只能以雙側擠壓，才可能充滿模具。模擬與實驗以ψ3沖頭單側加熱擠壓，只在單一側齒型充填並無法對另一側進行變型。以0.5mm/s的雙側擠壓速度能對材料雙側成形，由於兩側的充填體積不同造成ψ5沖頭對於24齒的模具還未充填完整，並須在往ψ5模穴進行擠壓才能充滿，晶粒的變化在齒型處全部細化，相對齒型充填也達到99%。在微齒輪的熱擠壓成型實驗，加熱有助於改善材料在塑性變形的成形，容易製作出高精度與高強度的微齒輪。

The size effect of micro-forming occurs in downsizing, non-uniform flow of material and can’t be predicted and traditional plastic theory can’t be used for simulation of micro-parts, the method for reducing the size effect in micro-forming was heat forming. Micro-forming processing is applied to micro-extension, micro-punching, micro-stamping, however, gear is largely applied in several areas, but doesn't have development of micro gear technology. The aim of this research is developing the forming technology of micro gears with involute micro spur gear, micro helical gear and micro double spur gear, and using titanium alloy heated squeezing to the fabrication of micro gears.
The specimen with diameter 5mm homogenization heat treatments resulting in different initial grain sizes with different hot tensile speeds to obtain mechanical properties, and operating finite element analysis (Deform 2D/3D) to predict the forming speed, forming force and geometry of micro gears. The squeezing speed of 0.5,1,10 mm/s with 400℃ forming temperature boundary in fabrication micro spur gear, founded that low squeezing speed (0.5, 1mm/s) can obtain the maximal die cavity filling rate. According to the die of skd-61 mechanical properties, if die heated over 600℃ was weakening of metal, therefore, the experimental temperature 500℃ and squeezing speed 0.5mm/s for squeezing micro spur gear, experiment results show that tooth profile of grain size in deddendum circle area grain refinement and enhanced mechanical properties, the cavity filling rate has a 99%. The boundary conditions of temperature 400℃ with squeezing speed 0.5 mm/s in micro helical gear simulation can fill the cavity, and different material grain sizes of cavity filling rate experimental can also 99%, effective filling rate factor of grain size is temperature. The fabrication of micro double spur gear only from squeezing two-side can fill the cavity, simulation and experiment show that used diameter 3mm of punch to squeeze one-side can’t succeed. The two-side squeezing speed 0.5mm/s to fabrication gear, but volume of gear forming is different can’t fill the cavity at the same time, it need to be squeezed again to obtain 99% of cavity filling rate. Hot squeezing experiment of micro gear, heating can improve the formation of materials on plastic deformation, more easily to fabrication high precision micro gear.

摘要.....i
Abstract.....ii
誌謝.....iv
目錄.....v
表目錄.....viii
圖目錄.....ix
符號說明.....xiii
第一章 緒論.....1
1-1 前言.....1
1-2 鍛造的優勢.....2
1-2-1 鍛造成型.....3
1-3 精密鍛造成型.....5
1-4 尺寸效應對微成形的影響.....8
1-4-1 尺寸效應對塑流應力的影響.....8
1-4-2 尺寸效應對精度的影響.....12
1-4-3 尺寸效應對摩擦的影響.....14
1-4-4 微成形的應用.....15
1-5 鈦合金鍛造與應用.....18
1-5-1 鈦合金特性.....18
1-5-2 鈦合金的應用.....18
1-6 研究重點.....20
1-7 論文架構.....21
第二章 微成形文獻探討.....22
2-1 介紹.....22
2-2 劇烈塑性變形(Severe Plastic Deformation, SPD).....22
2-3 劇烈塑性變形對於超細晶粒的成形機制.....25
2-4 微成形對於微零件的影響.....29
2-4-1 微引伸加工.....29
2-4-2 微擠製.....35
2-5 文獻探討小結.....38
第三章 研究方法與實驗設備.....39
3-1 研究目的.....39
3-2 擠壓製程的定義.....39
3-3 研究規劃.....39
3-4 實驗設備.....40
3-4-1 試片成分.....40
3-4-2 均質化退火熱處理.....41
3-4-3 金相實驗.....41
3-5 機械性質實驗.....41
3-5-1 拉伸實驗.....41
3-5-2 熱拉伸實驗.....42
3-6 齒型設計與模具製作.....45
3-6-1 微正齒輪設計(Micro spur gear).....46
3-6-2 微斜齒輪設計(Micro helical gear).....47
3-6-3 微雙階正齒輪設計(dual step spur gear).....49
3-6-4 模具製作.....51
3-6-5 油壓機.....52
3-7 齒型量測建立.....52
第四章 數值分析與實驗.....54
4-1 機械性質實驗.....54
4-1-1 常溫拉伸試驗.....54
4-1-2 熱拉伸試驗.....55
4-1-3 金相實驗.....59
4-1-4 硬度實驗.....60
4-2 微正齒輪實驗.....61
4-2-1 微正齒輪數值模擬.....61
4-2-2 微熱擠壓正齒輪.....64
4-2-3 熱擠壓加工晶粒與強度變化.....65
4-2-4不同晶粒尺寸之模具充填率.....68
4-3微斜齒輪實驗.....69
4-3-1 微斜齒輪數值模擬.....69
4-3-2 微熱擠壓斜齒輪.....71
4-3-3 熱擠壓加工晶粒與強度變化.....72
4-3-4不同晶粒尺寸之模具充填率.....75
4-4微雙階正齒輪實驗.....76
4-4-1 微雙階正齒輪數值模擬.....76
4-4-2熱擠壓微雙階正齒輪.....80
4-4-3 熱擠壓加工晶粒與強度變化.....81
4-4-4不同晶粒尺寸之模具充填率.....83
第五章 結果與討論.....85
5-1. 不同晶粒尺寸對熱拉伸的影響.....85
5-2 加工參數最佳化.....87
5-2-1 微正齒輪.....87
5-2-2 微斜齒輪.....88
5-2-3 雙階正齒輪.....88
5-3 齒輪充填率.....89
5-3-1 微正齒輪.....89
5-3-2 微斜齒輪.....89
5-3-3 微雙階齒輪.....90
5-4 齒輪硬度值.....90
第六章 結論.....91
6-1 未來展望.....92
參考文獻.....93
Extended Abstract.....100

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