Abstract One of the first attempts on fabricating functionally graded materials (FGMs) of titanium/hydroxyapatite (Ti/HA) with quasi-continuous ratios by selective laser melting (SLM) was done. HA ratios varied among the layers of FGMs from 0 wt% to 5 wt% with 1 wt% gradient. The 3D reconstruction of Ti/HA FGM bulk with micro-pores was presented through micro-CT, and the percentage of micro-pore increased from 0.01% to 3.18% with the increasing of HA ratio. The scanning electronic microscope results showed that the crack was positively correlated to HA ratio with the crack density increasing from 1.5 × 10− 4 μm/μm2 to 2.7 × 10− 3 μm/μm2. The microstructure evolution from 0% to 5% HA ratios could be elucidated as long lath-shaped grains → long acicular-shaped grains → short acicular-shaped grains → continuous circle-shaped grains → quasi-continuous circle-shaped grains, due to the perturbation in the melting pool and obstruction of crystal development by HA. Accordingly, the FGM provides a wide range of nanohardness from 5.11 to 8.36 GPa and Vickers hardness from 3.42 to 5.67 GPa. Moreover, the fracture toughness from 2% to 5% HA ratios ranges from 3.41 MPa m1/2 to 0.88 MPa m1/2, which can be tailored to fit that of cortical and cancellous bones.

中文翻译：

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SLM 制备的具有准连续比的钛/羟基磷灰石 (Ti/HA) 梯度材料：材料界面和断裂韧性

摘要 首次尝试通过选择性激光熔化 (SLM) 制备具有准连续比的钛/羟基磷灰石 (Ti/HA) 功能梯度材料 (FGM)。HA 比率在 FGM 层之间从 0 wt% 到 5 wt% 变化，梯度为 1 wt%。通过显微CT呈现具有微孔的Ti/HA FGM块体的3D重建，随着HA比例的增加，微孔的百分比从0.01%增加到3.18%。扫描电镜结果表明裂纹与HA比呈正相关，裂纹密度从1.5×10−4 μm/μm2增加到2.7×10−3 μm/μm2。从 0% 到 5% HA 比率的微观结构演变可以阐明为长条状晶粒 → 长针状晶粒 → 短针状晶粒 → 连续圆形晶粒 → 准连续圆形晶粒，由于HA 对熔池的扰动和晶体发育的阻碍。因此，FGM 提供了从 5.11 到 8.36 GPa 的广泛纳米硬度和从 3.42 到 5.67 GPa 的维氏硬度。此外，从 2% 到 5% HA 比率的断裂韧性范围从 3.41 MPa m1/2 到 0.88 MPa m1/2，可以定制以适应皮质和松质骨的断裂韧性。