Construction and application of a small-sized spray apparatus utilizing electrothermal explosion of spray powders to a study on the production of refractory spray coatings

研制了一种利用导电粉末电热爆炸制备耐火涂料的小型装置。喷涂熔点高于2800K的碳化物、硼化物和氮化物陶瓷粉末。因此，以下是一些新颖的结果：碳化钨和碳化钽的喷涂：为了使这些碳化钨和碳化钽的涂层致密且粘接，增加了陶瓷射流的流动密度。然后，喷涂陶瓷与衬底金属的混合量为30 ~ 50mum。此外，在混合层上获得了单层陶瓷的面涂层。这种分级涂层有望在金属基板上具有很强的附着力。硼化钛和氮化钛的喷射：提供给这些陶瓷粉末的能量增加，导致陶瓷和金属基底混合层的致密涂层。通过反复喷涂，获得了顶部为单层陶瓷的梯度涂层。然而，氮的非化学计量发生在氮化物中。反应喷涂复合涂层：钛与六方氮化硼混合粉末的电热爆炸形成了硼化钛与氮化硼陶瓷的复合涂层。这种陶瓷与金属基板表面混合。

A small-sized apparatus utilizing the electrothermal explosion of electrically conductive powders was constructed for the production of refractory spray coatings. It sprayd carbide, boride and nitride ceramic powders with melting points higher than 2800K.Thus, some novel results were found below ;1. Spray of tungsten carbide and tantalum carbide : In order to produce dense and adhesive coatings of these carbides, the flow density of the ceramic jets was increased. Then the mixing of sprayd ceramics and substrate metals ranged 30 to 50mum. In addition, the top coat of monolayr ceramics was obtained over the mixing layr. Such a graded coating was expected to be highly adhesive on metal substrates.2. Spray of titanium boride and nitride : The increase of energies supplied to these ceramic powders resulted in the dense coatings with mixing layr of the ceramics and metal substrates. The graded coatings with top monolayr ceramics were obtained by the repetition of the spray. However, nonstoichiometry of nitrogen happened in the nitride.3. Composite coating by reactive spray : The electrothermal explosion of a mixed powder of titanium and hexagonal boron nitride resulted in the composite coating of titanium boride and nitride ceramics. Such ceramics mixed with the surface of metal substrates.