鋁合金粉末鍛造製程之可行性研究

Feasibility Studies on Powder Forging Process for Aluminium Alloys

李榮顯(Rong Shean Lee) ； 吳錦龍(Jim Long Wu)

《鑛冶：中國鑛冶工程學會會刊》 34卷4期 (1990/12) Pp. 72-81

https://doi.org/10.30069/MM.199012_34(4).0009

摘要

傳統粉末冶金製程在鋁合金的製造方面，由於鋁粉表面氧化層在燒結時會阻礙分子的鍵結，因此大都採用液相燒結的方式，對於製程條件如燒结氣氛、溫度、時間等之控制亦較為嚴謹，因而亦提高其生產成本，及製造之困難度。而粉末鍛造則由於結合傳統粉末冶金及鍛造製程，可較經濟地生產高性能產品，然而製程變數間的關係亦更形複雜。本研究的目的即在探討鋁合金粉末鍛造製程變數（初始密度、燒結氣氛、預形設計等因子）對鍛造製品的性質影響，以了解可行之製程條件。文中建立了PM 201 AB鋁合金在適鍛溫度時的成形極限圖，且由視定塑性力學的分析，得到了擠鍛過程中材料的速度分佈及應變分佈以了解粉末鍛造之金屬流動方式。再由金相分析，了解粉末鍛造製程中緻密化之型態。由實驗結果可知鋁合金粉末燒結體確實可經由熱鍛而達到緻密化之效果，而其緻密化之程度與塑性加工之等效應變大小相關。研究之結果將可提供工業界試製鋁合金粉末鍛造產品時製程設計之參考。

並列摘要

Since the existence of oxide layer on aluminium powder surface impedes the bonding of particles, liquid phase sintering is usually used in powder metallurgy of aluminium to increase the speed of diffusion. In liguid phase sintering, very strict control of process conditions, such as atmosphere and temperature, is required; thus, it increases production cost and manufacture difficulty. An alternative process, powder forging, with the combination of powder metallurgy and conventional forging, can produce high performance product economically; however, the relation between process parameters is very complex and is so far little understood. The purpose of this research is to study the effects of process parameters, such as initial density, sintering atmosphere, and preform design, on the properties of aluminium alloy produced by powder forging, and then to obtain process conditions for feasible aluminium powder forging. The forming limit diagram of PM 201 AB aluminium alloy at the hot forging temperature for aluminium alloy is established. From the analysis of visioplasticity, the velocity field of extrusion forging process has been obtained and can be used for the verification of theoretical process simulation. By observing the metallography, the mechanism of densification in hot extrusion has been investigated. From the results of experiment, it conclude that the quality of the product obtained by. powder forging is better than conventional powder metallurgy and can be as good as conventional wrought material. The experimental results obtained in this study can be used for process design in powder forging of aluminium alloys.