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

本文介绍了一种利用导电粉末爆炸法制备耐火喷涂层的小型装置。本研究采用喷涂法制备了熔点高于2800K的碳化物、硼化物和氮化物陶瓷粉末。喷涂碳化钨和碳化钽：为了产生这些碳化物的致密和粘合涂层，陶瓷射流的流动密度增加。然后，喷涂陶瓷和基底金属的混合范围为30至50 μ m。此外，在混合层上获得了单层陶瓷的顶涂层。这种梯度涂层有望在金属基体上具有很高的附着力.硼化钛和氮化钛的喷涂：增加陶瓷粉末的能量，可获得致密的陶瓷涂层和金属基体的混合层。通过反复喷涂，获得了顶部为单层陶瓷的梯度涂层。但氮化物中存在非化学计量的氮.反应喷涂复合涂层：钛和六方氮化硼的混合粉末经爆炸处理，得到硼化钛和氮化物陶瓷的复合涂层。这类陶瓷与金属基体表面混合。

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.