氫氧基磷灰石與金纖維複合材料之機械性質

Abstract

氫氧基磷灰石的主要成分與生物骨頭的無機物成分相似，是極具生物相容性的外科植入材料。但是，即使合成氫氧基磷灰石的方法已發展了一段不短的時間；時至今日，人工合成的氫氧基磷灰石的缺點仍是其不高的機械性質。因此，許多研究團隊便嘗試製作氫氧基磷灰石的複合材料，希望能在不影響其良好生物相容性的條件下，有效提升氫氧基磷灰石的強度。 本研究以固態合成法製作氫氧基磷灰石，經球磨機以及攪磨機研磨出不同粒徑大小的氫氧基磷灰石粉末，再分別添加不同比例的金纖維進入兩種不同粒徑尺寸的氫氧基磷灰石基材中。將這些複合材料在1300℃的溫度下進行燒結。燒結之後的材料，相對密度會因為基材粒徑尺寸較小而有明顯提升；此外，金纖維的添加會產生類似觸媒的效果，促進相對密度與機械性質的改善。 本研究以四點彎曲的方式量測撓曲強度。HA/Au wire複合材的強度並未隨著第二相添加量之增加而有顯著提升，顯示金纖維並不會影響其撓曲強度的大小，由此可知，強度變化的趨勢是與密度有關。本研究以單邊切槽法(SENB)的方式量測破壞韌性，得到的結果顯示與強度測試有不同的趨勢，HA/Au wire的機械性質在Au wire微量添加下會大幅提升，顯示韌性的增加除了與密度有關之外，延性材料的添加亦扮演重要角色。

Hydroxyapatite (HA) is the bio-compatible material for surgical implants, at present, due to the major mineral constituents of it are similar to animals frames. Although the technique to synthesize HA has been developed for a long period, synthetic HA is still limited by its poor mechanical properties. In the present study, we have prepared two HA matrixes with different particle size and doping gold wire as the toughened phase in hydroxyapatite((Ca10(PO4)6(OH)2, HA) matrix which was synthesized by solid-state synthesis to form ceramic composite reinforcement and to expect the possible strategies to improve the toughness of HA are proposed. Solid-state synthesis was used to prepare the hydroxyapatute, and get two different size HA powder by ball milling and attrition mill methods. The different vatio of Au wire then add entered in two kinds of HA matrix that with different particle size. These composites undergo sintering at 1300℃.The relative density of these composites after sintering have obviously improved because the smaller particle size, and furthermore there are catalyst reaction by Au wire that better the densification and mechanical properties of composites. The flexural strength was determined by using the 4-point bending technique. The strength of HA/Au wire composites does not increase when a small amount of Au wire is added. It illustrated that the Au wire would not influence flexural strength. Thus it could be known, the strength variation of HA/Au wire composites corresponds closely to their density variation. The fracture toughness was determined by using the single-edge-notched beam method. The different results were obtained as that for strength. The toughness of HA/Au wire composites has superior increased by doping trace Au wire. The toughness data shows that the increase of toughness is related to density and the doped of Au ductility material.