Polished diamond coatings for dry tapering of aluminum

用于铝干式锥削的抛光金刚石涂层

• 批准号: 390771352
• 负责人: Professor Dr.-Ing. Frank Vollertsen
• 金额: --
• 依托单位: BIAS - Bremer Institut für Angewandte Strahltechnik GmbH
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/390771352?language=en
• 关键词: Polished; diamond; coatings; dry; tapering

Lubricants are used in forming technologies to lower friction and prevent adhesive wear. The use of lubricants combined with the chemical purification of the work pieces, which is necessary for subsequent processing, leads to a significant environmental impact.Preliminary investigations showed a low coefficient of friction of a polished diamond coating in a dry oscillating ball-on-plate tribometer test with an aluminum ball as counter body. Neither on the diamond coating nor on the alumina ball adhesion could be detected. The diamond coating did not show any wear after a test duration of 5.5 hours. The alumina ball showed an increase of the amount of oxide in the contact area, which might be explained by the occurring rise in temperature.The aim of the project is the realization of lubricant free tapering of aluminum with diamond coated tools. The hypothesis, which is supported by the tribometer tests, is, that sufficiently well polished diamond coatings enable dry forming of aluminum alloys. The production of polished polycrystalline CVD diamond coatings on reduction dies for economic prices represents a hurdle. The solution approach is that the coating deposition will be carried out with the CVD process which exists at BIAS. The polishing of the diamond coating should be realized for low costs in a two-stage process. Initially the roughness peaks are ablated using a picosecond laser and afterwards the final surface roughness will be achieved by commissioned mechanical polishing.Within the scope of the project reduction dies out of tungsten carbide will be coated with polycrystalline CVD diamond coatings. The aim is to achieve a homogenous coating thickness on the inner wall of the die. Furthermore it will be examined which surface roughness can be obtained by the use of a picosecond laser. The procedure of laser ablation has to be transferred onto the geometry of the reduction die. Throughout the project duration forming tests of the tapering of aluminum alloys will be examined dry as well as lubricated.

润滑剂用于成形技术中以降低摩擦并防止粘着磨损。润滑剂的使用与后续加工所需的工件化学净化相结合，会对环境产生重大影响。初步研究表明，抛光金刚石涂层在干式振荡球-板摩擦试验机中的摩擦系数较低，该试验采用铝球作为相对体。在金刚石涂层和氧化铝球上都没有检测到粘附。在5.5小时的测试持续时间之后，金刚石涂层没有显示出任何磨损。氧化铝球在接触区域显示出氧化物数量的增加，这可能是由温度的上升所解释的。该项目的目的是实现用金刚石涂层刀具对铝进行无润滑锥形加工。摩擦试验机试验支持的假设是，充分抛光的金刚石涂层能够实现铝合金的干式成形。在还原模具上生产抛光的多晶CVD金刚石涂层以获得经济的价格是一个障碍。解决方法是涂层沉积将采用BIAS现有的CVD工艺进行。金刚石涂层的抛光应在两阶段工艺中以低成本实现。首先使用皮秒激光器烧蚀粗糙度峰值，然后通过委托机械抛光实现最终的表面粗糙度。在项目范围内，碳化钨还原模具将涂覆多晶CVD金刚石涂层。目的是在模具的内壁上实现均匀的涂层厚度。此外，它将检查表面粗糙度可以通过使用皮秒激光获得。激光烧蚀的过程必须转移到缩小模具的几何形状上。在整个项目期间，将对铝合金锥形的成形试验进行干燥和润滑检查。