STTR Phase I: Cold Gas Dynamic Spray Processing of Bioactive Nano-hydroxyapatite/Titanium Nanocomposite Coatings

这个第一阶段的小型企业技术转移(STTR)项目将测试用水热纳米羟基磷灰石(n-HA)和微米级钛制造生物活性涂层的可行性。这两种成分将通过摩擦研磨或机械融合来加工，以制造纳米复合材料原料。冷气动力喷涂(CGDS)技术将被用于在含有高体积分数n-HA微晶的钛衬底上形成多孔钛涂层。例如，预计生物植入物上的这种涂层将促进天然骨的内生长，促进植入物与周围骨材料的附着。CGDS工艺是一种以粉末为原料制备功能涂料的新方法。粉末颗粒被加速到超音速(马赫2)，获得足够高的动能，在与基材碰撞时形成致密的涂层。CGDS工艺与传统的喷涂工艺的不同之处在于，它不依赖热能来熔化喂料粉末或促进结合。瞬间键合完全是由于动能在1微秒的时间尺度上的耗散。由于加工温度通常为200℃，CGDS加工是保持纳米颗粒尺寸和温度敏感晶体化学的理想选择，例如在n-HA生物材料中。CGDS工艺将被证明是一种多功能、成本效益高的方法，可以利用纳米结构粉末的特性来制造功能表面。由于CGDS涂层面积大、形状复杂，并可应用于各种材料，因此在人类医疗和兽医假体植入方面将具有广泛的商业影响。

This Phase I Small Business Technology Transfer (STTR) project will test the feasibility of making bioactive coatings from hydrothermal nanostructured hydroxyapatite (n-HA) and micron-size titanium. The two components will be processed by attritor milling or mechanofusion to make a nanocomposite feed stock. Cold Gas Dynamic Spray (CGDS) processing will be used to form a porous titanium coating on titanium substrates that contain a high volume fraction of n-HA crystallites. It is expected that such coatings on bioimplants, for example, would promote the in-growth of natural bone, facilitating attachment of the implant to surrounding bone material. CGDS processing is a new way to form functional coatings from powder feedstocks. Powder particles are accelerated to supersonic speeds (Mach 2) achieving high kinetic energy sufficient to form a dense coating upon impact with a substrate. CGDS processing differs from conventional spray processes in that it does not rely on thermal energy to melt the feed powder or to promote bonding. Instant bonding is due solely to the dissipation of kinetic energy on a time scale of 1 microsecond. Since the processing temperature is typically 200 C, CGDS processing is ideal for maintaining the nanograin-size and temperature sensitive crystal chemistries such as in n-HA biomaterials. The CGDS process will prove to be a versatile, cost-effective way to fabricate functional surfaces that exploit the properties of nanostructured powders. Since CGDS can coat large areas, complex shapes, and can be applied to a variety of materials it will have wide commercial impact applications for human medical and veterinary prosthetic implants.