共查询到18条相似文献,搜索用时 313 毫秒
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采用粉末冶金工艺制备了TaC质量分数分别为0%,2%,4%和6%的Ti(C,N)基金属陶瓷,通过压痕-急冷法研究了TaC含量对其抗热震性能的影响。结果表明,随热震次数的增多,金属陶瓷中的裂纹长度增加;裂纹主要沿陶瓷相/金属相界面以及在金属相中扩展;含TaC质量分数为2%的金属陶瓷晶粒细小,且分布均匀,环形相厚度适中,在500℃多次热震后裂纹扩展最缓慢,抗弯强度和硬度损失量最小,抗热震性能最好;热震后Ti(C,N)基金属陶瓷的硬度损失很小,但残余抗弯强度显著下降。 相似文献
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利用化学沉积方法对表面改性后的碳纳米管进行进行镍包覆,在Ti(C,N)基金属陶瓷中添加不同含量的碳纳米管作为增强相,采用粉末冶金法制备了碳纳米管增强的Ti(C,N)基金属陶瓷材料;研究了碳纳米管的表面改性、加入量及烧结温度对金属陶瓷性能的影响。结果表明:当pH值为4.5时得到的镍镀层比pH值为9时得到的镍镀层连续光滑;当碳纳米管含量由0增加到0.5%(质量分数)时,Ti(C,N)基金属陶瓷的抗弯强度随碳纳米管含量的增加而升高,1 420℃烧结时,其抗弯强度最大。 相似文献
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《机械工程材料》2017,(7)
基于WC与Mo_2C对Ti(C,N)基金属陶瓷的组织优化和润湿性改善等方面具有相似的作用,研究了WC和Mo_2C的添加对Ti(C,N)基金属陶瓷在高温下显微硬度的影响。结果表明:随着温度的升高,添加WC和Mo_2C后金属陶瓷的高温显微硬度均呈下降趋势,在600~800℃范围内,添加WC后金属陶瓷的高温显微硬度略高于添加Mo_2C金属陶瓷的,当温度达到900℃时,两者的显微硬度几乎相同;随着温度的升高,两种金属陶瓷的压痕面积、平均压痕深度均逐渐增加;添加WC后金属陶瓷的高温真应变明显小于添加Mo_2C金属陶瓷的,但当温度达到900℃时,两种金属陶瓷的高温变形量接近。 相似文献
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采用真空烧结法制备了纳米SiC晶须增强Ti(C,N)基金属陶瓷复合材料,用XRD、FESEM、EDS、万能试验机及维氏硬度仪等手段研究了纳米SiC晶须对复合材料显微组织和抗弯强度及断裂韧度的影响。结果表明:复合材料的显微组织具有典型的芯-壳结构,主要由黑色的硬质核心相,灰色的环形相,灰白色的粘结相以及部分分布于外环形相/粘结相界面、部分弥散分布于粘结相中的白色增强相组成;随着纳米SiC晶须添加量的增加,粘结相的体积分数减小,增强相的体积分数增大;与未添加晶须的金属陶瓷相比,复合材料的抗弯强度和断裂韧度均有显著提高,当纳米SiC晶须的体积分数为7.5%时,复合材料的力学性能最佳,抗弯强度为2 346 MPa,断裂韧度为16.82 MPa·m~(1/2)。 相似文献
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通过直接添加与原位生成两种方式引入Y_2O_3作为烧结助剂,热压烧结制备了AlN陶瓷;研究了添加方式及添加量对AlN陶瓷显微结构和力学性能的影响。结果表明:原位生成烧结助剂的方式更有利于AlN陶瓷的致密化,特别是当原位生成的Y_2O_3质量分数为2%时,AlN陶瓷的相对密度达到99.0%,硬度为15.39GPa,抗弯强度为383.0MPa,均高于直接添加Y_2O_3的;同时可获得晶形完整、第二相含量少且大部分位于三叉晶界、晶粒间面-面接触的显微结构;随着原位生成烧结助剂添加量的增多,陶瓷的相对密度下降,在AlN晶界处出现大量第二相而导致陶瓷的硬度、抗弯强度等力学性能也下降。 相似文献
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利用粉末冶金方法制备了名义成分(质量分数/%)为Ni-10Al-xCr-0.6Y_2O_3(x=5,10,15,20)合金,研究了铬含量对烧结后合金物相组成、显微组织、高温抗氧化性能及室温力学性能的影响。结果表明:随着铬含量的增加,合金中的孔洞减少,相对密度增大,硬度和抗弯强度提高;当烧结温度为1 270℃、铬质量分数为20%时合金的性能最优,硬度和抗弯强度分别为352 HV和1 605 MPa;高含量铬促进了连续致密Al_2O_3保护膜的生成,从而降低了合金的氧化速率,提高了合金的高温抗氧化性能。 相似文献
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采用真空液相烧结技术制备了Mo_2FeB_2基金属陶瓷,研究了钒添加量(质量分数,0~7.5%)对其组织和力学性能的影响。结果表明:当钒添加量不大于2.5%时,金属陶瓷的孔隙率无明显变化,当钒添加量大于2.5%时,金属陶瓷中的孔隙明显增多,金属陶瓷的致密性下降;钒的添加对金属陶瓷的相组成无显著影响,Mo_2FeB_2硬质相均匀分布在铁基黏结相中;当钒添加量为2.5%时,硬质相呈长条状且明显细化;当钒添加量大于2.5%时,硬质相发生团聚,且形貌由长条状向等轴状转变;随着钒添加量的增加,金属陶瓷的硬度、抗弯强度和断裂韧度均先增后降,当钒添加量为2.5%时均达到最大值,分别为90.6HRA、2 350MPa和15.1MPa·m~(1/2)。 相似文献
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Effects of Cr3C2 on the erosion–corrosion behavior of Ti(C,N)-based cermets are studied in alkaline conditions. The results indicate that the erosion–corrosion resistance of cermets is improved with proper Cr3C2 content. Corrosion performance of cermets is deteriorated by Cr3C2 addition in NaOH solution. With the increase of Cr3C2, the erosion–corrosion behavior of Ti(C,N)-based cermets is classified to be erosion regime, erosion–corrosion regime, corrosion–erosion regime and corrosion regime. Materials degradation is determined by particles erosion for cermets with low Cr3C2 content, while for materials containing more Cr3C2 addition, binder corrosion and subsequent erosion are responsible for materials deterioration. 相似文献
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VC对微米级Ti(CN)基金属陶瓷微观结构和力学性能的影响 总被引:1,自引:0,他引:1
VC对于制备微米级的Ti(CN)基金属陶瓷,能够起到控制Ti(CN)晶粒长大的作用,并且能够使烧结体中晶粒粒度分布变得均匀。在液相烧结过程中,由于瓦尔德熟化效应使Ti(CN)晶粒长大,Ti(CN)晶粒的长大又分为连续长大和不连续长大。关于VC的抑制机理,目前还没有明确的结论,但有三种比较有代表性的说法:吸附机制、溶解机制和偏析机制。随着VC添加量的增加,Ti(CN)基金属陶瓷的抗弯强度呈现先升后降的趋势;VC的加入使材料的硬度减小。 相似文献
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The erosive wear resistance of cermets with different composition, structure and properties has been investigated. It was shown that the erosive wear resistance of cermets can not be estimated only by hardness, characterizing resistance to penetration. The differences in wear resistance between cermet materials with equal hardness levels can be attributed to differences in their resistance to fracture and fracture toughness. The mechanism of erosion depends first on testing conditions. The present paper discusses some features of the material removal process during particle-wall collision. Systematic studies of the influence of the impact variables on the collision process have been carried out. 相似文献
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Mechanical properties and features of erosion of cermets 总被引:5,自引:0,他引:5
The erosive wear resistance of cermets with different composition, structure and properties has been investigated. It has been shown that cermets erosive wear resistance cannot be estimated only by hardness, characterised by resistance to penetration. The differences in wear resistance between cermet materials with equal hardness level can be attributed to differences in their resistance to fracture. The present paper discusses some features of the material removal process during the particle–wall collision. Solid particle erosion tests on eight materials have been performed using silicon carbide and silica abrasive particles within a range of erodent size of 0.1–0.3 mm, impact angles from 30 to 90° and particle velocity from 30 to 80 m s−1. In order to clarify the details of the impact, the process of interaction of solid particles with cermet targets was studied using a laser Doppler anemometer (LDA) measuring technique. Systematic studies of the influence of the impact variables on the collision process have been carried out. 相似文献