Investigation of the mechanisms during sintering process modifications of multi-component sputter materials and the phase specific deposition of AlCrSi(W,Ta)N

本研究项目研究了多组分靶材料烧结过程的相互作用，这些过程随后被用于纳米复合材料结构的形成。由纳米晶颗粒（nc (Al,Cr)N）嵌套在非晶基体（a-Si3N4）中的AlCrSiN体系是该结构的基础。这个项目的目的是通过在涂层系统中点缀钨和钽来了解导致硬度增加以及抗磨损和抗氧化的机制。通过对CrSi（W, Ta）体系烧结工艺的基本分析，合成了具有低孔隙率的靶段，并将其嵌入整体铝体中。在热压CrSi（W, Ta）的同时，改变烧结参数，如温度、压力、烧结时间和支持扩散和压实的化学计量。到目前为止，所产生的扩散和相形成机制尚未被探索。采用纳米粉末对难熔金属W和Ta进行分散，以加快其扩散速度。粉末涂层避免了粉末颗粒团聚，通过电弧pvd应用，以实现颗粒在烧结段中的均匀分布。在模拟辅助选择基本材料的基础上，实现了固/液相烧结，以促进金属间相的平衡形成，从而确定工艺修改引起的孔隙率最小化机制。反应沉积的AlCrSi(W, Ta)N层的纳米结构通过CrSi（W, Ta）段的化学计量变化以及Al靶中的段数与靶材料中的金属间相相关。在研究AlCrSi(W, Ta)N薄膜时，Si， W和Ta含量的变化是特别有趣的，因为它们既可以细化晶粒，也可以实现固溶硬化机制，从而对硬度，磨损和抗氧化性产生积极影响。本研究项目的总体目标是将新目标材料的化学成分和相组成之间相互作用的分析结果与纳米复合材料结构的摩擦力学涂层性能进行整体结合。特别地，研究了W和Ta含量对氧化行为的影响。最后，将测试的AlCrSi(W, Ta)N涂层体系应用于刀具上，分析掺杂元素的影响，并在实际生产条件下验证这些影响。

This research project investigates interactions of sintering processes for multi-component target materials, which are subsequently used for the formation of nanocomposite structures. The AlCrSiN system, consisting of nanocrystalline grains (nc (Al,Cr)N), embedded in an amorphous matrix (a-Si3N4), is the basis for this structure. It is the aim of this project to understand the mechanisms that lead to an increase of the hardness as well as the wear and oxidation resistance by doting the coating system with tungsten and tantalum. Fundamental analyses of sintering processes for the CrSi(W, Ta) system are used to synthesize target segments with a low porosity, which are embedded in a monolithic aluminum body.Sintering parameters such as the temperature, pressure, sintering time and the stoichiometry that support diffusion and compaction, are modified while hot pressing CrSi(W, Ta). So far, the resulting diffusion and phase formation mechanisms have not been explored. Finely dispersed nanopowders are used for the refractory metals W and Ta to accelerate the diffusion velocity. Powder particle agglomerations are avoided by powder coatings, applied by means of Arc-PVD to achieve a homogenous distribution of particles in the sintered segments. Based on a simulation-assisted selection of the basic materials, sintering with solid/liquid phases is realized to foster a balanced formation of intermetallic phases in order to identify porosity-minimizing mechanisms caused by process modifications. The nanostructures of reactively deposited AlCrSi(W, Ta)N layers are correlated with the intermetallic phases in the target material by stoichiometric variations in the CrSi(W, Ta) segments as well as the number of segments in the Al target. The variations of Si, W, and Ta contents are of particular interest when investigating AlCrSi(W, Ta)N films as they enable both grain-refining as well as solid solution hardening mechanisms, thus positively influencing the hardness, wear, and oxidation resistance.The overall objective of this research project is to holistically combine the results of the analyses of the interactions between the chemical compositions and phase compositions of new target materials with the resulting tribo-mechanic coating properties of nanocomposite structures. Especially, the influence of the W and Ta contents on the oxidation behavior is closely scrutinized. Finally, the examined AlCrSi(W, Ta)N coating systems will be applied on cutting tools to analyze the influence of the doping elements and to verify these influences under real production conditions.