含尺寸與黏附雙重效應之三體微接觸理論分析與驗證

Theoretical Analysis and Experimental Verification of Three-Body Microcontact Model with Multi-Scale and Adhesion Effects

徐柏銓(Bai-Chiuan Shiu)

指導教授 ： 洪政豪

國立虎尾科技大學/工程學院/機械與機電工程研究所/碩士(2008年)

摘要

微機電系統的發展已逐漸從學術研究走進產業界，越來越多的研究專注在微機電系統，包含了光學通訊、高密度儲存器、綠色能源與生物醫學等多種知識與技術。微機電元件體積在逐漸微小化的同時，黏附與磨擦等表面力現象相對於慣性力就越來越顯得重要。在微機械或精密機械具有相對運動之接觸表面間，實際上常存有不同外來粒子、磨屑或液體膜等，而這些因素均會影響接觸面間之黏附、磨擦、磨損與熱效應。因此本文建立一個界面存有顆粒、液體及表面具有粗糙度的三體微接觸黏附模式，以了解顆粒及液體表面效應在兩接觸界面間對微接觸特性的影響。
本文理論分析考慮黏附與顆粒之三體微接觸模式，並利用彈性、塑性、彈塑性變形接觸面積，推導出具有尺寸效應之黏附磨擦係數、波峰變形磨擦係數、顆粒變形磨擦係數與棘輪磨擦係數，建立界面間具有尺寸效應之完整磨擦特性模式，以了解顆粒、表面材料及表面效應在兩接觸界面間磨擦特性的影響。實驗印證部分則是利用奈米測試儀(nano test)之壓痕與刮痕實驗，量測材料機械性質與磨擦力，再以原子力顯微鏡(AFM)進行接觸表面之黏附力量測實驗，其測量結果與理論分析結果比對顯示，磨擦力與黏附力皆隨著施加負荷的增加而增加，其誤差均在可接受的範圍下，證明理論建構之微接觸方程式有ㄧ定的可信度。因此，本文理論分析結果可作為現今最熱門之電鑄技術、半導體產業製程與微機電設計之參考。

關鍵字

微機電系統 ； 黏附 ； 磨擦 ； 磨損 ； 顆粒 ； 三體微接觸 ； 變形 ； 尺寸效應

並列摘要

The development of the micro-electromechanical system (MEMS) has already come into the industrial application from the academic research gradually, more and more attention is being paid on the research in MEMS, include such many kinds of knowledge and technology as optical communication, high density storage, green energy and biomedicine. Adhesion and friction become more important than inertial force, when the volume of a micro-device is decreased. In the MEMS and precision machine, particles and liquid films are often presented at contact interfaces, these factors will affect the adhesion, friction, wear and thermal properties between the contact surfaces.In this paper, a three-body adhesion model for rough surfaces with particles and liquid films are proposed in order to understand the effects of particles and liquid films between surfaces on contact characteristics.
This work establishes a new three-body contact model to calculate elastic contact area, plastic contact area, elastic-plastically deformed contact area, adhesion friction, deformation friction and ratchet friction between the contact surfaces. The second objective is manipulation AFM and NanoTest to compare date. The results show that the particle size dominates the friction value for low mean separation between rough surfaces. Beyond the critical value of mean separation, the important factor in affecting total friction value is surface friction. The critical value have the sequence for the different plasticity index: (d/σ)Ψ2.5 > (d/σ) Ψ1.5 > (d/σ) Ψ0.5. The larger the wear particle size, the higher friction value and critical separation value for three materials under the same operation conditions. Capillary force and contact force decreases with the increase in dimensionless mean separation for the same film thickness. Capillary forces ratio of nickel is larger than the materials of steel and silicon under the same roughness parameters.

並列關鍵字

MEMS ； adhesion ； friction ； wear ； particle ； three-body microcontact ； deformation ； scale effect

參考文獻

參考文獻

[1] Lu L., 1995, “Formation of Wear Particles in Polishing of Brittle Solids and Grinding of Metals,” Ph.D. thesis. School of industrial Engineering, Purdue University, West Lafayette, IN47907-1287.

[2] Ahn Y., 1992, “Deformation About Sliding Indentation in Ceramics and Its Application to Lapping,” Ph.D. thesis. School of Industrial Engineering, Purdue University, West Lafayette, IN47907-1287.

[3] Wang L. Y., Sullivan M. and Chao J, 2001, “Thermal Asperties Sensitivity to Particles: Methodology and Test Results,” ASME Journal of Tribology, Vol. 123, pp. 376-379.

[4] Zhang L., Kok, R., Yuen Y. and Lam E., 1999, “Particle induced damage on heads and discs due to fine particles of different materials,” IEEE Trans on Magnetics, Vol.35, pp.927-932.