Diffusional reactions of the components of a VK hard alloy with tungsten

Conclusions The diffusional reactions in the systems W-C, W-Co, and WC-Co result in the formation of solid solutions and intermetallic compounds in the diffusion zones in accordance with the relevant constitution diagrams. In the diffusional reaction zone in the system W-WC, the tungsten carbide-WC forms without the participation of a third component.VK is the general designation of WC-Co hard alloys; VK6, also referred to in this article, is a WC-6% Co alloy. — Translator.Translated from Poroshkovaya Metallurgiya, No. 4 (148), pp. 79–82, April, 1975.     

熔融制样-X射线荧光光谱法测定硬质合金中钨钴镍铁铌钽铬

采用高纯氧化物经四硼酸锂和碳酸锂熔融制样制备单一氧化物熔融细粉,称取不同质量单一熔融细粉混合后二次熔融合成各元素含量不同的硬质合金人工标准样品,制作校准曲线,选用经验系数法进行基体校正,建立了无定值标样下X射线荧光光谱法(XRF)测定钨钴或钨镍类钨基硬质合金中钴、镍、铁、铌、钽、铬、钨元素的分析方法。各元素校准曲线线性范围宽,相关系数均大于0.998。对人工配制标准样品的精密度进行考察,结果的相对标准偏差(RSD)小于0.5%;对硬质合金样品进行精密度考察,精密度良好。准确度验证结果表明,测定结果与GB/T 26050-2010的测试结果及化学法测定值吻合。方法的建立解决了硬质合金定值标准样品难于获得的问题。     

An investigation of hot corrosion morphology by color X-ray distribution imaging

The structure of corrosion layers on nickel-base alloys resulting from reaction with sulfur dioxide and sodium sulfate at elevated temperatures (hot corrosion) has been studied by the method of color X-ray distribution imaging. This technique involves the preparation of color composite prints by superimposing primary color images of the individual element X-ray distributions on a single sheet of color film. By a proper choise of primary tints, the distribution of reaction products and other features of thé corrosion morphology can be clearly defined as a result of color mixing in the composite micrograph. The distribution of corrosion products in the surface layers of Ni-Cr and Ni-Al alloys and an IN 738 specimen following sulfidation was investigated using this technique.     

Calculation of the structural and thermodynamic constants of normal chromium spinels

The interstructural distances and crystal lattice parameters of complex chromium spinels of variable composition having five different cations are determined according to the earlier developed procedure taking into account their crystal lattices and calculated effective ionic radii. Using these structural characteristics, the enthalpy of the crystal lattice and the enthalpy of spinel formation are calculated. The composition-lattice parameter and composition-enthalpy of the formation diagrams are constructed for (Mg _i ²⁺ Fe _j ²⁺ )O · (Fe _x ³⁺ Al _y ³⁺ Cr _z ³⁺ )₂O₃ spinels. They make it possible to determine the lattice parameter and the enthalpy of oxide formation for any spinel composition.     

An investigation of hot corrosion morphology by color X-ray distribution imaging

The structure of corrosion layers on nickel-base alloys resulting from reaction with sulfur dioxide and sodium sulfate at elevated temperatures (hot corrosion) has been studied by the method of color X-ray distribution imaging. This technique involves the preparation of color composite prints by superimposing primary color images of the individual element X-ray distributions on a single sheet of color film. By a proper choise of primary tints, the distribution of reaction products and other features of thé corrosion morphology can be clearly defined as a result of color mixing in the composite micrograph. The distribution of corrosion products in the surface layers of Ni-Cr and Ni-Al alloys and an IN 738 specimen following sulfidation was investigated using this technique.     

电感耦合等离子体原子发射光谱法测定钴铬钨合金中钨镍铁钒

采用盐酸、硝酸溶解样品,再加硫磷混酸冒烟,冒烟期间滴加硝酸使碳化物完全溶解,采用基体匹配法配制标准溶液系列消除基体效应的影响,选择W 207.911nm、Ni 231.604nm、Fe 259.940nm、V 311.071nm为分析线,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定钴铬钨合金中钨、镍、铁、钒。钨的质量分数在0.1%~30%范围内,镍、铁、钒的质量分数在0.1%~10%范围内各元素质量分数与对应的发射强度呈线性,校准曲线线性相关系数不小于0.9997;方法中各元素检出限为0.0008%~0.0033%(质量分数)。按照实验方法测定两个钴铬钨合金中钨、镍、铁、钒,结果的相对标准偏差(RSD,n=6)为1.0%~1.9%;并与微波消解-电感耦合等离子体原子发射光谱法的测定结果进行对比,测定结果基本一致。     

An X-ray diffraction investigation of BN-Si and BN-Si3N4 solid solutions

Translated from Poroshkovaya Metallurgiya, No. 7(331), pp. 84–88, July, 1990.