用注入成形工藝做成最小的骨頭置換物
       利用微金屬粉末注入成形，研究者現(xiàn)在能制成微小的埋植劑像鐙骨，鐙骨是人耳中最小的骨頭，一般用生物相容性材料如，鈦制成。
      “我們制成纖小的聽小骨的精密復(fù)制品，用極細(xì)的金屬粉末注入成形能使我們復(fù)制出這些組織。”來自德國不來梅Fraunhofer制造工藝和實(shí)用材料研究所（IFAM）的Philipp Imgrund解釋道，迄今為止，這種小金屬部件產(chǎn)品還應(yīng)用蝕刻或碾磨技術(shù)，這些一直是種非常復(fù)雜并耗時的工藝過程，并且并不適用于許多金屬，雖然有金屬注入成形（micro－MIM）,科學(xué)家們能夠混合或改造不同類型的材料，這在相當(dāng)長的一段時間里用不銹鋼制做小部件成為可能，現(xiàn)在，研究能夠不使用組織相容性材料，如，鈦，鈦合金來制造這些微笑精細(xì)的部件。在一個調(diào)控裝置系列中，研究者制出300多個5.4mg重0.3mm厚的微小部件，“我們現(xiàn)在裝備上馬了micro－MIM的系列產(chǎn)品” Imgrund強(qiáng)調(diào)道“以鐙骨為例，我們證明了這一工序的極限和可行性。”
      在注入成形微小部件之前，研究人員將一種有機(jī)黏合劑與微金屬粉末混合，于是這種混合物就能像處理塑料制品一樣在注入成形機(jī)上進(jìn)行處理，隨后，黏合劑被排出隨之混合物就燒結(jié)成一個高密度物質(zhì)。Imgrund解釋說：“我們改進(jìn)粉末和黏合劑使之與注入成形和燒結(jié)工藝過程相配，我們的目標(biāo)是――獲得可再生的高品質(zhì)，不管是為了制成非常復(fù)雜的微小組織還是為了完備這些組織所要求的其他功能。”
來源于：德國弗勞恩霍夫應(yīng)用研究促進(jìn)協(xié)會

Bones: Smallest Substitutes with Injection Molding
     By means of micro metal powder injection molding, researchers can now produce tiny implants like the stirrup, a small bone in the human ear, from biocompatible materials such as titanium.
   “We make exact copies of this delicate ossicle. Injection molding with very fine metal powder enables us to replicate these tiny structures,” explains Philipp Imgrund of the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research IFAM in Bremen. Until now, the production of tiny metal parts using techniques such as etching or milling has been a very complex and time-consuming process, and not suitable for many types of metal. With micro metal powder injection molding (micro-MIM), however, the scientists are able to combine and shape different types of material. It has been possible for a long time to produce tiny parts from stainless steel. Now the researchers are in a position to make such small, delicate components out of biocompatible materials such as titanium and titanium alloys. In a pilot series, the researchers manufactured 300 miniature parts with a weight of 5.4 milligrams each and a wall thickness of only 0.3 millimeters. “We are now ready to start series production with the micro-MIM process,” Imgrund stresses. “Using the stirrup as an example, we are demonstrating the limits and possibilities of the process and of the new materials.”

     Before injection-molding miniature parts, the researchers mix the fine metal powder with an organic binding agent. The mixture can then be processed on an injection molding machine in the same way as a plastic. Following this, the binding agent is expelled from the component, which is then sintered to a high density. “We vary the powder and binding agent and are developing suitable injection-molding and sintering processes. Our objective is to achieve reproducibly high quality for very complex micro-components and to equip these components with additional functions as required,” explains Imgrund.

  Source: Fraunhofer-Gesellschaft