Przekop Robert E, Kujawa Maciej, Pawlak Wojciech, Dobrosielska Marta, Sztorch Bogna, Wieleba Wojciech
Centre for Advanced Technologies, Adam Mickiewicz University Poznan, 61-712 Poznań, Poland.
Faculty of Mechanical Engineering, Wroclaw University of Science and Technology, 50-370 Wrocław, Poland.
Polymers (Basel). 2020 May 29;12(6):1250. doi: 10.3390/polym12061250.
With the development of 3D printing technology, there is a need to produce printable materials with improved properties, e.g., sliding properties. In this paper, the authors present the possibilities of producing composites based on biodegradable PLA with the addition of graphite. The team created composites with the following graphite weight contents: 1%, 2.5%, 5%, 7.5%, and 10%. Neat material was also subjected to testing. Tribological, mechanical, and chemical properties of the mentioned materials were examined. Measurements were also made after keeping the samples in ageing and climatic ovens. Furthermore, SEM observations of samples before and after friction tests were carried out. It was demonstrated that increasing graphite content caused a significant decrease in wear (PLA + 10% graphite had a wear rate three times lower than for a neat material). The addition of graphite did not adversely affect most of the other properties, but it ought to be noted that mechanical properties changed significantly. After conditioning in a climatic oven PLA + 10% graphite has (in comparison with neat material) 11% lower fracture stress, 47% lower impact strength, and 21% higher Young's modulus. It can be certainly stated that the addition of graphite to PLA is a step towards obtaining a material that is low-cost and suitable for printing sliding spare parts.
随着3D打印技术的发展，需要生产具有改进性能（如滑动性能）的可打印材料。在本文中，作者介绍了基于可生物降解的聚乳酸（PLA）并添加石墨来生产复合材料的可能性。该团队制备了石墨重量含量分别为1%、2.5%、5%、7.5%和10%的复合材料。还对纯材料进行了测试。对上述材料的摩擦学、力学和化学性能进行了研究。在将样品置于老化箱和气候试验箱后也进行了测量。此外，还对摩擦试验前后的样品进行了扫描电子显微镜（SEM）观察。结果表明，增加石墨含量会导致磨损显著降低（PLA + 10%石墨的磨损率比纯材料低三倍）。添加石墨对大多数其他性能没有不利影响，但应该注意的是，力学性能发生了显著变化。在气候试验箱中进行老化处理后，PLA + 10%石墨（与纯材料相比）的断裂应力低11%，冲击强度低47%，杨氏模量高21%。可以肯定地说，在PLA中添加石墨是朝着获得一种低成本且适合打印滑动备件的材料迈出的一步。
