Abstract

The microstructure and microhardness of eleven volumetric cermets based on TiC carbide with nickel- and cobalt-based matrices after liquid-phase sintering at a temperature of 1400°C were studied. It is proposed to use the research results for the subsequent production of powders for plasma spraying of coatings. The compositions of the matrices and the contents of additional hardening phases and carbon were selected taking into account the specific features of the formation of plasma coatings: a decrease in the carbon content and high solidification rates of the sprayed particles with the formation of additional nanosized carbides and an increase in the volume fraction of carbides from 70 to 88%. The traditional composition for cermets with TiC carbide, NiCr–Mo, and industrial powders such as PG-SR2 grade (PN-CrNi80Si2B2) with the composition (wt %) Ni, 13.5 Cr, 2.7 Si, 4.5 Fe, 0.37 C, 1.65 B and TAFA 1241F grade with the composition (wt %) Co, 32 Ni, 21 Cr, 8 Al, 0.5 Y were used as the matrix. The ring zone on TiC carbide is formed by sintering with the participation of WC, Cr₃C₂, TiN, matrix phases, and 1–2.8 wt % of additional carbon in the composition of cermets. As a result, the initial volume fraction of TiC carbide increases from 70 to 88%. Additional carbon is also consumed to decrease the oxygen content at the sintering stage (the reduction of oxides). Upon sintering, the cermets have high microhardness values of 1940–3210 kgf/mm² at an indentation load of 20 G and lower values at an indentation load of 200 G, which can be explained by the scale factor. The calculated maximum contribution of the hardness of the hardening phases to the hardness of the cermet was assessed for cermets with a Co matrix at 3681 kgf/mm².

中文翻译：

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等离子喷涂的基于TiC的金属陶瓷

摘要

研究了在1400°C的温度下液相烧结后的11种基于TiC碳化物的镍基和钴基基体的金属陶瓷的显微组织和显微硬度。建议将研究结果用于随后的等离子喷涂涂料粉末的生产中。选择基质的组成以及其他硬化相和碳的含量时要考虑到等离子体涂层形成的特殊特征：碳含量的降低和喷涂颗粒的高凝固速率以及形成其他纳米级碳化物的能力碳化物的体积分数从70％增加到88％。TiC碳化物，NiCr–Mo，以及工业粉末，例如成分为（wt％）Ni，重量百分比为Ni，13.5 Cr，2.7 Si，4.5 Fe，0.37 C，1.65 B的PG-SR2级（PN-CrNi80Si2B2）和Co（成分为wt％）的TAFA 1241F级，使用32 Ni，21 Cr，8 Al，0.5 Y作为基体。TiC碳化物上的环带是通过在WC，Cr的参与下烧结而形成的金属陶瓷成分中含有₃ C ₂，TiN，基体相和1-2.8 wt％的额外碳。结果，TiC碳化物的初始体积分数从70％增加到88％。在烧结阶段还消耗了额外的碳以降低氧含量（减少氧化物）。烧结后，金属陶瓷在20 G的压痕载荷下具有1940–3210 kgf / mm ^2的高显微硬度值，在200 G的压痕载荷下具有较低的显微硬度值，这可以由比例因子来解释。对于Co基体为3681kgf / mm ²的金属陶瓷，评估了计算的硬化相硬度对金属陶瓷硬度的最大贡献。