英语翻译本文采用放电等离子烧结技术（SPS）制备AlN/BN复相陶瓷,同时根据BN含量不同调整烧结助剂Y2O3的添加剂.

英语翻译
本文采用放电等离子烧结技术（SPS）制备AlN/BN复相陶瓷,同时根据BN含量不同调整烧结助剂Y2O3的添加剂.在极大提高烧结效率的同时,提高材料抗弯强度,有效减缓因引入BN对复相陶瓷导热性能的劣化,实现了材料综合性能的统一.研究了晶粒起始尺寸和烧结助剂添加量对AlN陶瓷相组成、显微结构以及性能的影响.重点研究了影响AlN/BN复相陶瓷显微结构和性能的因素.通过烧结工艺和烧结助剂添加量的改变调整AlN/BN的显微结构,提高复相陶瓷的导热性能,使其在提高可加工性的同时,保持较高力学性能和导热性能.
SPS制备单相AlN陶瓷,烧结温度在1800℃,保温时间10min,样品相对密度可达98.5%以上,硬度约11.5Gpa,抗弯强度在300Mpa以上.AlN起始粒径尺寸和烧结助剂添加量,对致密度和力学性能几乎没有影响,但对对材料的显微结构和导热性能有显著影响.起始粒径为1.3μm的AlN粉末添加3wet%Y2O3的试样,热导率达到148W/m∙k.AlN粉末的起始粒径和Y2O3的添加量影响AlN的晶体发育、晶界相的分布以及AlN晶粒之间的接触,从而影响热导率.
AlN/BN复相陶瓷在烧结温度1600-1800℃,保温时间0-10min的工艺条件下可以快速致密,BN含量在5-30vol%范围内,致密度均达到98%以上.材料的硬度则随着BN含量的增加而线性降低,从而改善可加工性,BN含量达到10vol%时,复相陶瓷的硬度已低于硬质合金刀具的硬度,从而可以机械加工.
BN含量在10vol%时,晶粒细化增韧的作用远远大于弱相劣化作用,复相陶瓷的强度较AlN单相陶瓷有较大提高,继续增加含量至25vol%,强度呈下降趋势,但仍比单相陶瓷强度高.
BN含量达到5vol%以上时,复相陶瓷的热导率较单相AlN陶瓷明显降低,在15vol%-25vol%的范围内,热导率表现出相对稳定的变化趋势,下降幅度变缓.第二相BN的起始粒径尺寸对复相陶瓷的显微组织结构和导热性能有显著影响.BN起始颗粒尺寸过小,显微结构中的团聚现象明显,不利于热导率的优化.
进一步研究AlN/BN复相陶瓷热导率的影响因素并对其进行优化.根据BN的具体含量调整烧结助剂Y2O3的添加量,探讨烧结温度和保温时间,可以调控复相陶瓷的显微结构,有效提高复相陶瓷热导率.BN含量为15vol%,Y2O3添加量为8wet%时,烧结温度1800℃,保温时间10min,获得热导率141W/m∙k,可加工性优异的复相陶瓷.
本文采用SPS制备的AlN/BN复相陶瓷所获得的高热导率已远远超过国内外采用热压烧结制备的AlN/BN复相陶瓷的最高水平,而且拥有同样优异的可加工性能和力学强度.而借助SPS可以在实现AlN/BN复相陶瓷快速致密化基础上进行相组成及显微组织的调控.SPS工艺的烧结温度要比热压烧结工艺的烧结温度（1850-1900℃）低100~200℃,SPS的保温时间也较热压烧结的保温时间1-3h大大缩短,极大地提高了烧结效率,这对于AlN/BN可加工复相陶瓷的高性能、高效率制备和应用有重要的意义.

This paper spark plasma sintering (SPS) of AlN / BN composite ceramics,as the BN in different adjustment sintering additives Y2O3 additives.Significantly improve the efficiency of the sintering and improve flexural strength materials,due to the introduction of effective mitigation BN ceramic thermal conductivity of the composite performance degradation and realizing the reunification of the material properties.On the initial grain size and amount of sintering aids AlN ceramics phase composition,microstructure and properties of.Focused on the impact of AlN / BN composite ceramic microstructure and properties of factors.Through sintering process and the amount of sintering aids change adjustment AlN / BN microstructure of composite ceramics improve the thermal performance to improve machinability in the same time,maintaining a relatively high thermal conductivity and mechanical properties.
Preparation of single-phase SPS AlN ceramics,the sintering temperature in 1800 ℃,soaking time 10 min,the relative density of samples up to more than 98.5 percent,about 11.5 Gpa hardness,bending strength of more than 300 Mpa.AlN initial particle size and amount of sintering aids,density and mechanical properties of almost no impact,but on the material microstructure and thermal conductivity have a significant impact on performance.Initial diameter of 1.3 μ m of AlN powder add 3% Y2O3 wet samples,thermal conductivity to 148 W / m ∙ k.AlN powder particle size and the initial Y2O3 impact of the addition of AlN crystal growth,the distribution of grain boundary phase,as well as the contact between the AlN grains,thus affecting the thermal conductivity.
AlN / BN composite ceramic sintering temperature in the 1600-1800 ℃,and the holding time of 0-10 min under the conditions can quickly compact,vol BN content in the 5-30% range,the density reached more than 98%.With the hardness of the material content of the BN to increase linearly decreased,thereby improving machinability,BN content of 10 vol%,the composite ceramics has been lower than the hardness of the hardness of cemented carbide cutting tools,which can be mechanical processing.
BN content in 10 vol%,the role of grain refinement toughening of deterioration is far greater than the weak,the strength of composite ceramics than single-phase AlN ceramics has improved greatly,and continue to increase the content to 25 vol%,a declining trend strength,but still higher than the single-phase high-strength ceramics.
BN content reaches more than 5 vol%,the composite ceramic thermal conductivity of a single-phase AlN ceramics significantly decreased in 15 vol% 25vol%-within the scope of the thermal conductivity show the trend of changes in relative stability,rate of decline slows.BN second phase of the initial particle size of the ceramic composite microstructure and thermal conductivity properties of the structure has had a notable impact.BN initial particle size too small,microscopic structure of the reunion phenomenon obviously not conducive to optimizing the thermal conductivity.
Further study AlN / BN composite ceramic thermal conductivity factors and the impact of its optimization.BN under the specific content of the adjustment of sintering aids Y2O3 content on the sintering temperature and soaking time can be controlled composite ceramic microstructure,effectively enhance the composite ceramic thermal conductivity.BN content of 15 vol% Y2O3 wet content is 8%,the sintering temperature 1800 ℃,soaking time 10 min,access to thermal conductivity of 141 W / m ∙ k,excellent machinability of composite ceramics.
Preparation of this paper SPS AlN / BN composite ceramics obtained by the high thermal conductivity have been far more than at home and abroad by hot-pressing of the AlN / BN composite ceramics of the highest level,but also has the same excellent processability and mechanical properties of strength .The SPS can help in achieving the AlN / BN composite ceramics rapid densification on the basis of the composition and microstructure of the regulation.SPS process of sintering temperature than hot-pressing process of sintering temperature (1850-1900 ℃) low 100 200 ℃,the SPS holding time than the hot-pressing the holding time 1-3 h significantly reduced,thus greatly enhancing the efficiency of sintered In this regard AlN / BN Machinable Ceramic Composites,high-performance,high efficiency,preparation and application of great importance
软件翻译!仅供参考!