Thermally sprayed Zn2TiO4 heating coatings with adaptive electrothermal properties

在初步工作中，开发了一种金属加热层的替代品，即在二氧化钛基底上热喷涂半导体加热层，并证明了其可操作性。其优点被称为组件表面上更均匀的热分布和全平面涂层所涉及的工作量低。工作温度限制在300 °C是最主要的缺点。随着超越，它涉及氧化和电阻的不可逆增加，这相当于加热层的破坏。 使用钛酸锌（Zn 2 TiO 4），应实现更好的温度稳定性，因此创建新一代热喷涂加热层系统。借助Zn_2TiO_4的性质和应用范围，论证了其温度稳定性。作为热喷涂涂层的应用到目前为止仅在实验室毕业时才知道，并且需要密集的开发工作。悬浮液和前体的计划使用是合理的，因为它们在厚而均匀的涂层微观结构方面具有优势。应该检查的一个重要优势是供体对电热涂层性能的特定改性。悬浮液喷涂应用技术的综合开发工作（喂料技术、注射器、悬浮液和涂层的开发）为新型Zn_2TiO_4加热层的开发奠定了基础，其电热性能可直接由施主改变，为理解这种相互作用，开发工作必须获得科学资助。第一步是考察悬浮液和前驱体的形成;第二步是围绕喷涂工艺的影响研究涂层的形成;第三步是分析和了解供体对所得涂层性能的影响。这是一个问题，以澄清以下假设：A）涂层从Zn 2 TiO 4可以生产的悬浮液和前体的热喷涂。B）涂层从Zn 2 TiO 4是热稳定性比TiOx或TiO 2/20 Cr2 O3。C）掺杂MnO和NiO影响的电-热性能的Zn 2 TiO 4加热层（如电阻率和热行为）。D）通过使用前体的施主可以产生在一个混合晶体中的层。 E）通过使用悬浮液喷涂的S-HVOF罐预期的更致密的涂层结构，实现了比使用S-APS更好的电性能。 该物质科技基础是应用研究项目的编制对象。在该项目的后期过程中，MnO或NiO供体的替代物可以证明长期稳定，适应性强的加热层的设定目标。

In the preliminary works an alternative to metallic heating layers was developed in thermally sprayed semiconducting heating layers on titanium dioxide base and their operability was demonstrated. As advantages are to be called the more homogeneous heat distribution on the component surface and the low amount of workload involved by full-flat coating. The limitation of the operating temperature on 300 °C is the most essential disadvantage. With an overstepping it comes to oxidation and irreversible increase of the electrical resistance what amounts to a destruction of the heating layer. With zinc titanate (Zn2TiO4) a better temperature stability should be achieved and therefore a new generation in thermally sprayed heating layer systems be created. With the help of the properties and ranges of application of Zn2TiO4 the temperature stability was demonstrated. An application as a thermal spray coating is known up to now only in the lab graduation and needs intensive development work. The planned use of suspension and precursor is justified by their advantages concerning a thick and homogeneous coating micro structure.An essential advantage which should be examined is the specific modification of the electric-thermal coating properties by donors. The comprehensive development works of the appli-cants with suspension spraying (development of: feeder technology, injectors, suspensions and coatings) form the base of new Zn2TiO4-heating layers to whose electric-thermal properties can be modified by donors straight.It is necessary for the development works to win a scientific funded base for the understanding of the interaction. This concerns in the first step to examine the development of suspen-sion and precursor and in the second step the coating development around the influence of the spray processes and in the third step to analyze and to understand the influencing of donors on the resultant coating properties. It is a matter the following hypotheses to clear up:A) Coatings from Zn2TiO4 can be produced of suspension and precursor by thermal spraying.B) Coatings from Zn2TiO4 are thermally more stable than TiOx or TiO2 / 20Cr2O3.C) Doping from MnO and NiO influence the electric-thermal properties of Zn2TiO4-heating layers (e.g. resistivity and thermal behavior).D) By the use of precursors the donors can be produced in a mixing crystal in the layer. E) By the denser coating structure to be expected with the S-HVOF can with the suspension spraying better electrical properties are achieved than with the S-APS. This material-scientific-technological base is to be compiled the object of the applied research project. In the later course of the project a substitution of MnO-or NiO-donors is possible to prove the set goal of a longtime stable, adaptable heating layer.