KrF excimer laser precision machining of hard and brittle ceramic biomaterials.
KrF excimer laser precision machining of porous hard-brittle ceramic biomaterials was studied to find a suitable way of machining the materials into various desired shapes and sizes without distorting their intrinsic structure and porosity. Calcium phosphate glass ceramics (CPGs) and hydroxyapatite (HA) were chosen for the study. It was found that KrF excimer laser can cut both CPGs and HA with high efficiency and precision. The ablation rates of CPGs and HA are respectively 0.081 µm/(pulse J cm(-2)) and 0.048 µm/(pulse  J cm(-2)), while their threshold fluences are individually 0.72 and 1.5 J cm(-2). The cutting quality (smoothness of the cut surface) is a function of laser repetition rate and cutting speed. The higher the repetition rate and lower the cutting speed, the better the cutting quality. A comparison between the cross sections of CPGs and HA cut using the excimer laser and using a conventional diamond cutting blade indicates that those cut by the excimer laser could retain their intrinsic porosity and geometry without distortion. In contrast, those cut by conventional machining had distorted geometry and most of their surface porosities were lost. Therefore, when cutting hard-brittle ceramic biomaterials to prepare scaffold and implant or when sectioning them for porosity evaluation, it is better to choose KrF excimer laser machining.
Department of Biomedical Engineering, Ji Nan University, Guang Zhou, People's Republic of China.
Yao-Xiong
YX
Huang
Jian-Yi
JY
Lu
Jin-Xia
JX
Huang
D001672:Biocompatible Materials / Q000737:chemistry* / Q000528:radiation effects; D002130:Calcium Phosphates / Q000737:chemistry* / Q000528:radiation effects; D002516:Ceramics / Q000737:chemistry* / Q000528:radiation effects; D019245:Compressive Strength / Q000528:radiation effects; D017886:Durapatite / Q000737:chemistry* / Q000528:radiation effects; D006244:Hardness / Q000528:radiation effects; D006358:Hot Temperature; D054018:Lasers, Excimer; D008422:Materials Testing; D013499:Surface Properties / Q000528:radiation effects
D001672:Biocompatible Materials; C022107:Bioglass; D002130:Calcium Phosphates; D017886:Durapatite; C020243:calcium phosphate