高爾夫桿頭合金材料機械性質之探討

Evolution of Mechanical Properties of Golf Club Head Alloys

高爾夫球桿自1980年代起有了突破性的革命，無論是桿身或桿頭皆從木質材料演進至碳纖維或金屬材料，以致擊球距離越來越遠，最低桿紀錄屢創新低，比賽熱烈的程度越來越高。本研究以近30年球桿頭使用材料的發展，從柿木、鐵系合金、不銹鋼、鈦或少數其它金屬的過程進行分析。從研究的結果發現，桿頭演進的趨勢循著追求遠距與操控性，因此在材質的要求是以機械性質強又具高延伸率為主，機械性質強是期能創造更高的彈簧效益達到距離遠的目標，高延伸率是希望擊球擁有最佳的操控打感。同時也發現金屬材料也以輕量化為趨勢，鈦合金具有質輕密度佳高強度的特性，適用於製造大型化桿頭，所以目前開球木桿90%以上都使用鈦合金為主流材料，但因不斷的創新與進步，近年在規則上就設置開球木桿彈簧效益(coefficient of restitution, COR、characteristic time, CT)的限制，避免距離不斷增加，以致球場設計改善因應不及。

Golf clubs have undergone revolutionary breakthroughs since the 1980s. With the materials used for club shafts or heads evolved from woods to carbon fibers or metals, driving distance became longer. The record for lowest strokes has been broken repeatedly and the competition level has become more intense. This study analyzed the development of club head materials from persimmon wood, iron alloy, stainless steel to titanium or other metals. The results indicate that the trend of golf club heads development is guided by longer flight distances and excellent control. Therefore, the requirements for material characteristics are superior mechanical properties and higher elongation rates. Superior mechanical property enhances the spring-like effect that can improve flight distance., Higher elongation rate provides optimal control. It was also found that metal materials tends to be lighter in weight. Titanium alloy is a light metal with low density and high strength. It is suitable for larger size of club heads. Currently, more than 90% of drivers adopt titanium alloy as the primary material. However, due to continuing innovations and advancements, golf rules has been trying to limit spring-like effects for drivers (COR and CT)in recent years to prevent constantly increasing driving distance that new golf course design may not be able to improve with the same pace.