{"title":"Synthesis of niobium carbonitride by self-propagating combustion of Nb–C system in nitrogen","authors":"C.L. Yeh, Y.D. Chen","doi":"10.1016/j.ceramint.2004.11.008","DOIUrl":null,"url":null,"abstract":"<div><p><span><span>An experimental investigation on the preparation of niobium<span> carbonitrides by self-propagating high-temperature synthesis (SHS) was conducted using compacted samples of niobium and carbon powders ignited in gaseous nitrogen. Effects of the carbon content, nitrogen pressure, and </span></span>NbN addition on the combustion behavior and the degree of conversion were studied. Due to the nature of reaction in the combustion front, steady propagation of the combustion wave is observed in the sample of Nb</span> <!-->+<!--> <!-->0.3C, whereas the flame front associated with the samples of Nb<!--> <!-->+<!--> <!-->0.5C and Nb<!--> <!-->+<!--> <!-->0.7C travels in an oscillatory manner. Moreover, the flame-front propagation velocity was found to decrease with an increase in the carbon content of the sample. For the samples of Nb<!--> <!-->+<!--> <!-->0.3C and Nb<!--> <!-->+<!--> <!-->0.5C, after the passage of the combustion front the reaction continues lengthily in an afterburning stage, resulting in the nitridation percentage as high as about 80% that is nearly unaffected by the variation of nitrogen pressure. However, due to the lack of afterburning combustion the degree of nitridation in the sample of Nb<!--> <!-->+<!--> <!-->0.7C was decreased to between 53 and 67%. The XRD analysis of final products indicates that in addition to the dominant phase of Nb(C,N), there exist small amounts of Nb and carbon left unreacted.</p></div>","PeriodicalId":267,"journal":{"name":"Ceramics International","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.ceramint.2004.11.008","citationCount":"16","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ceramics International","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0272884204004997","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 16
Abstract
An experimental investigation on the preparation of niobium carbonitrides by self-propagating high-temperature synthesis (SHS) was conducted using compacted samples of niobium and carbon powders ignited in gaseous nitrogen. Effects of the carbon content, nitrogen pressure, and NbN addition on the combustion behavior and the degree of conversion were studied. Due to the nature of reaction in the combustion front, steady propagation of the combustion wave is observed in the sample of Nb + 0.3C, whereas the flame front associated with the samples of Nb + 0.5C and Nb + 0.7C travels in an oscillatory manner. Moreover, the flame-front propagation velocity was found to decrease with an increase in the carbon content of the sample. For the samples of Nb + 0.3C and Nb + 0.5C, after the passage of the combustion front the reaction continues lengthily in an afterburning stage, resulting in the nitridation percentage as high as about 80% that is nearly unaffected by the variation of nitrogen pressure. However, due to the lack of afterburning combustion the degree of nitridation in the sample of Nb + 0.7C was decreased to between 53 and 67%. The XRD analysis of final products indicates that in addition to the dominant phase of Nb(C,N), there exist small amounts of Nb and carbon left unreacted.
期刊介绍:
Ceramics International covers the science of advanced ceramic materials. The journal encourages contributions that demonstrate how an understanding of the basic chemical and physical phenomena may direct materials design and stimulate ideas for new or improved processing techniques, in order to obtain materials with desired structural features and properties.
Ceramics International covers oxide and non-oxide ceramics, functional glasses, glass ceramics, amorphous inorganic non-metallic materials (and their combinations with metal and organic materials), in the form of particulates, dense or porous bodies, thin/thick films and laminated, graded and composite structures. Process related topics such as ceramic-ceramic joints or joining ceramics with dissimilar materials, as well as surface finishing and conditioning are also covered. Besides traditional processing techniques, manufacturing routes of interest include innovative procedures benefiting from externally applied stresses, electromagnetic fields and energetic beams, as well as top-down and self-assembly nanotechnology approaches. In addition, the journal welcomes submissions on bio-inspired and bio-enabled materials designs, experimentally validated multi scale modelling and simulation for materials design, and the use of the most advanced chemical and physical characterization techniques of structure, properties and behaviour.
Technologically relevant low-dimensional systems are a particular focus of Ceramics International. These include 0, 1 and 2-D nanomaterials (also covering CNTs, graphene and related materials, and diamond-like carbons), their nanocomposites, as well as nano-hybrids and hierarchical multifunctional nanostructures that might integrate molecular, biological and electronic components.