Pub Date : 2024-10-22DOI: 10.1016/j.ijrmhm.2024.106930
Cheng Chen , Qingfang Yun , Changhua Chen , Xingwei Xu , Jianfeng Zhao , Qingxian Li , Wei Wang , Tijun Li , Zhixing Guo , Ji Xiong , Junbo Liu
The plasma nitriding process was conducted on a TiCN-based cermet that had been coated with a multilayer CrAl/CrAlBN coating deposited via cathodic arc. The intensity of the plasma nitriding was modified by adjusting the anode current of the ionization source. To investigate the interface conditions, techniques such as electron probe X-ray microanalysis, electron backscatter diffraction, and transmission electron microscopy were employed. The results indicated that increasing the anode current led to the formation of a thicker nitrided layer and an increase in the texture coefficient of the (111) plane. Specifically, at an anode current of 200 A, the lattice mismatch degree at the TiCN/CrAlN interface decreased from 16.4 % to 3.7 %, resulting in the formation of a nearly coherent interface. The hardness, adhesion strength, and H/E ratio of the coating reached their peak values, and the coated cutting tool exhibited optimal cutting performance when machining the GH4149 superalloy.
等离子氮化过程是在通过阴极电弧沉积了多层 CrAl/CrAlBN 涂层的 TiCN 基金属陶瓷上进行的。通过调节电离源的阳极电流来改变等离子氮化的强度。为了研究界面条件，采用了电子探针 X 射线显微分析、电子反向散射衍射和透射电子显微镜等技术。结果表明，增加阳极电流会导致形成更厚的氮化层，并增加（111）面的纹理系数。具体来说，在阳极电流为 200 A 时，TiCN/CrAlN 界面的晶格失配度从 16.4 % 降至 3.7 %，从而形成了近乎一致的界面。涂层的硬度、附着强度和 H/E 比均达到峰值，涂层切削工具在加工 GH4149 超合金时表现出最佳切削性能。
{"title":"Substrate modification for high performance CrAl/CrAlBN multilayers coated TiCN-based cermet through plasma nitriding","authors":"Cheng Chen , Qingfang Yun , Changhua Chen , Xingwei Xu , Jianfeng Zhao , Qingxian Li , Wei Wang , Tijun Li , Zhixing Guo , Ji Xiong , Junbo Liu","doi":"10.1016/j.ijrmhm.2024.106930","DOIUrl":"10.1016/j.ijrmhm.2024.106930","url":null,"abstract":"<div><div>The plasma nitriding process was conducted on a TiCN-based cermet that had been coated with a multilayer CrAl/CrAlBN coating deposited via cathodic arc. The intensity of the plasma nitriding was modified by adjusting the anode current of the ionization source. To investigate the interface conditions, techniques such as electron probe X-ray microanalysis, electron backscatter diffraction, and transmission electron microscopy were employed. The results indicated that increasing the anode current led to the formation of a thicker nitrided layer and an increase in the texture coefficient of the (111) plane. Specifically, at an anode current of 200 A, the lattice mismatch degree at the TiCN/CrAlN interface decreased from 16.4 % to 3.7 %, resulting in the formation of a nearly coherent interface. The hardness, adhesion strength, and H/E ratio of the coating reached their peak values, and the coated cutting tool exhibited optimal cutting performance when machining the GH4149 superalloy.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106930"},"PeriodicalIF":4.2,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.ijrmhm.2024.106927
Qinzhi Huang, Qingrui Lin, Yang Xu, Yong Cao
To identify potential superhard materials, we conducted a comprehensive theoretical investigation of the thermodynamic and kinetic stability, mechanical properties, electronic structure, Debye temperatures and melting point of sixteen ternary transition metal borides NbTMBx (x = 1, 2, 4 and TM = Ti, V, Fe, Co, Ni, Zr, Ru, Hf, W, Os) using first-principles methods. Our findings indicate that, with the exception of NbFeB, NbRuB, and NbWB, all other borides exhibit both thermodynamic and kinetic stability. Notably, NbTiB4, NbVB4, NbZrB4 and NbHfB4 demonstrate superior hardness and enhanced resistance to deformation, with NbTiB4 showing an impressive hardness value of 40.84 GPa, positioning it as a promising candidate for superhard materials. Both NbVB4 and NbTiB4 have very high Debye temperatures and melting points and can be used in high temperature environments. We further explored the mechanical properties of NbTiB4 at elevated temperatures by employing a combination of first-principles and quasi-static methods. Our analysis reveals that the elastic constants and moduli of NbTiB4 decrease with increasing temperature. Additionally, bonding analysis indicates that all NbB ternary borides exhibit hybridization involving metallic, ionic, and covalent interactions, resulting in the formation of exceptionally strong covalent bonds between boron atoms.
{"title":"Predicting potential hard materials in NbB ternary boride: First-principles calculations","authors":"Qinzhi Huang, Qingrui Lin, Yang Xu, Yong Cao","doi":"10.1016/j.ijrmhm.2024.106927","DOIUrl":"10.1016/j.ijrmhm.2024.106927","url":null,"abstract":"<div><div>To identify potential superhard materials, we conducted a comprehensive theoretical investigation of the thermodynamic and kinetic stability, mechanical properties, electronic structure, Debye temperatures and melting point of sixteen ternary transition metal borides NbTMB<sub>x</sub> (x = 1, 2, 4 and TM = Ti, V, Fe, Co, Ni, Zr, Ru, Hf, W, Os) using first-principles methods. Our findings indicate that, with the exception of NbFeB, NbRuB, and NbWB, all other borides exhibit both thermodynamic and kinetic stability. Notably, NbTiB<sub>4</sub>, NbVB<sub>4</sub>, NbZrB<sub>4</sub> and NbHfB<sub>4</sub> demonstrate superior hardness and enhanced resistance to deformation, with NbTiB<sub>4</sub> showing an impressive hardness value of 40.84 GPa, positioning it as a promising candidate for superhard materials. Both NbVB<sub>4</sub> and NbTiB<sub>4</sub> have very high Debye temperatures and melting points and can be used in high temperature environments. We further explored the mechanical properties of NbTiB<sub>4</sub> at elevated temperatures by employing a combination of first-principles and quasi-static methods. Our analysis reveals that the elastic constants and moduli of NbTiB<sub>4</sub> decrease with increasing temperature. Additionally, bonding analysis indicates that all Nb<img>B ternary borides exhibit hybridization involving metallic, ionic, and covalent interactions, resulting in the formation of exceptionally strong covalent bonds between boron atoms.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106927"},"PeriodicalIF":4.2,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-19DOI: 10.1016/j.ijrmhm.2024.106924
Wenquan Li, Hongxia Zhou, Chenghong Wang
In order to enhance the wear resistance of cold-sprayed Ti coatings, Ti-diamond (Ti-MD) composite coatings were fabricated, followed by heat treatment at different temperatures. The effects of heat treatment temperature on the wear resistance of the composite coatings were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microhardness testing, and wear resistance experiments. The results show that the composite coating undergo no phase transformation after heat treatment, and exhibits higher microhardness and improved wear resistance. The porosity results showed that the porosity of the coating decreased as the heat treatment temperature increases. TEM results showed that stable TiC (about 10 nm) was formed at the interface between the titanium and diamond particles after heat treatment at 800 °C, and nanoindentation results showed that the heat-treated coating had higher deformation resistance. Specifically, when the heat-treated temperature rose to 800 °C, the composite coating exhibits an 80 % reduction in wear rate, primarily attributable to the decreased porosity of the coating and the enhanced adhesion between Ti and diamond particles. The wear mechanisms of the heat-treated coatings are predominantly reduced oxidative and abrasive wear.
为了提高冷喷涂钛涂层的耐磨性，制作了钛-金刚石（Ti-MD）复合涂层，然后在不同温度下进行热处理。采用 X 射线衍射 (XRD)、扫描电子显微镜 (SEM)、透射电子显微镜 (TEM)、显微硬度测试和耐磨性实验评估了热处理温度对复合涂层耐磨性的影响。结果表明，复合涂层在热处理后没有发生相变，并表现出更高的显微硬度和更好的耐磨性。孔隙率结果表明，涂层的孔隙率随着热处理温度的升高而降低。TEM 结果表明，在 800 °C 热处理后，钛和金刚石颗粒之间的界面上形成了稳定的 TiC（约 10 nm），纳米压痕结果表明，热处理后的涂层具有更高的抗变形能力。具体而言，当热处理温度升至 800 ℃ 时，复合涂层的磨损率降低了 80%，这主要归功于涂层孔隙率的降低以及钛和金刚石颗粒之间附着力的增强。热处理涂层的磨损机制主要是减少氧化磨损和磨料磨损。
{"title":"Effect of heat treatment on wear resistance of cold-sprayed Ti-diamond composite coating","authors":"Wenquan Li, Hongxia Zhou, Chenghong Wang","doi":"10.1016/j.ijrmhm.2024.106924","DOIUrl":"10.1016/j.ijrmhm.2024.106924","url":null,"abstract":"<div><div>In order to enhance the wear resistance of cold-sprayed Ti coatings, Ti-diamond (Ti-MD) composite coatings were fabricated, followed by heat treatment at different temperatures. The effects of heat treatment temperature on the wear resistance of the composite coatings were assessed using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microhardness testing, and wear resistance experiments. The results show that the composite coating undergo no phase transformation after heat treatment, and exhibits higher microhardness and improved wear resistance. The porosity results showed that the porosity of the coating decreased as the heat treatment temperature increases. TEM results showed that stable TiC (about 10 nm) was formed at the interface between the titanium and diamond particles after heat treatment at 800 °C, and nanoindentation results showed that the heat-treated coating had higher deformation resistance. Specifically, when the heat-treated temperature rose to 800 °C, the composite coating exhibits an 80 % reduction in wear rate, primarily attributable to the decreased porosity of the coating and the enhanced adhesion between Ti and diamond particles. The wear mechanisms of the heat-treated coatings are predominantly reduced oxidative and abrasive wear.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106924"},"PeriodicalIF":4.2,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-19DOI: 10.1016/j.ijrmhm.2024.106925
Chaoping Jiang, Ruoyi Zhao, Lei Shi, Fengying Zhang
xW-Ni (x = 60, 70, 80, 90 wt%) coatings were prepared by laser cladding on the surface of X80 steel substrate to explore the effects of different W contents on the microstructure, corrosion resistance, microhardness and corrosion-wear properties of the WNi coatings. The results revealed that the microstructure of the various WNi coatings composed of W and γ (Ni, Fe) phases. The increase in W content resulted in more W atoms being dissolved in the γ (Ni, Fe) phase, enhancing the solid solution strengthening effect, which increased the average microhardness of the coating. Moreover, the addition of W provided diffusion channels for metal ions to migrate to the surface of the coating for passivation film formation, which improved the corrosion resistance of the coating. However, the addition of excessive amounts of W caused the coating density to decrease and accelerated galvanic corrosion. The 80 W-Ni coating among the studied coatings exhibited excellent corrosive-wear resistance due to its high hardness and good corrosion resistance. This coating corrosive-wear mechanism was the combination of abrasive wear and corrosion.
采用激光熔覆方法在 X80 钢基体表面制备了 xW-Ni（x = 60、70、80、90 wt%）涂层，以探讨不同 W 含量对 WNi 涂层的微观结构、耐腐蚀性、显微硬度和腐蚀磨损性能的影响。结果表明，不同 WNi 涂层的微观结构由 W 相和γ（Ni、Fe）相组成。W 含量的增加使更多的 W 原子溶解在 γ（Ni、Fe）相中，增强了固溶强化效应，从而提高了涂层的平均显微硬度。此外，W 的添加为金属离子迁移到涂层表面形成钝化膜提供了扩散通道，从而提高了涂层的耐腐蚀性。然而，过量 W 的添加会导致涂层致密性降低，加速电化学腐蚀。在所研究的涂层中，80 W-Ni 涂层因其高硬度和良好的耐腐蚀性而表现出优异的耐腐蚀磨损性。该涂层的腐蚀磨损机理是磨料磨损和腐蚀的结合。
{"title":"Effect of W content on microstructure and corrosion-wear properties of WNi coatings by laser cladding","authors":"Chaoping Jiang, Ruoyi Zhao, Lei Shi, Fengying Zhang","doi":"10.1016/j.ijrmhm.2024.106925","DOIUrl":"10.1016/j.ijrmhm.2024.106925","url":null,"abstract":"<div><div>xW-Ni (x = 60, 70, 80, 90 wt%) coatings were prepared by laser cladding on the surface of X80 steel substrate to explore the effects of different W contents on the microstructure, corrosion resistance, microhardness and corrosion-wear properties of the W<img>Ni coatings. The results revealed that the microstructure of the various W<img>Ni coatings composed of W and γ (Ni, Fe) phases. The increase in W content resulted in more W atoms being dissolved in the γ (Ni, Fe) phase, enhancing the solid solution strengthening effect, which increased the average microhardness of the coating. Moreover, the addition of W provided diffusion channels for metal ions to migrate to the surface of the coating for passivation film formation, which improved the corrosion resistance of the coating. However, the addition of excessive amounts of W caused the coating density to decrease and accelerated galvanic corrosion. The 80 W-Ni coating among the studied coatings exhibited excellent corrosive-wear resistance due to its high hardness and good corrosion resistance. This coating corrosive-wear mechanism was the combination of abrasive wear and corrosion.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106925"},"PeriodicalIF":4.2,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.ijrmhm.2024.106920
Aleksandr I. Gusev
Based on the analysis of phase diagrams of carbide-forming systems M–C (M = Ti, Zr, Hf), an empirical relationship is proposed between the elastic stiffness constants cij of nonstoichiometric cubic carbides of titanium, zirconium and hafnium and their melting temperature. The dependences of the melting temperatures of nonstoichiometric cubic carbides TiCy, ZrCy and HfCy on their composition in homogeneity regions are calculated using the elastic stiffness constants c11(y) and c44(y) of these carbides. The calculated maximum melting temperatures are observed for carbides ∼TiC0.80, ∼ZrC0.82 and ∼ HfC0.94–0.95 and are equal to 3345, 3708 and 4192 K, respectively. There is a qualitative correlation between the concentration dependences of the melting temperatures Tm(y) of TiCy, ZrCy and HfCy carbides and the anisotropy of the elastic properties of these carbides.
{"title":"Melting temperature and elastic constants of disordered nonstoichiometric cubic TiCy, ZrCy and HfCy carbides","authors":"Aleksandr I. Gusev","doi":"10.1016/j.ijrmhm.2024.106920","DOIUrl":"10.1016/j.ijrmhm.2024.106920","url":null,"abstract":"<div><div>Based on the analysis of phase diagrams of carbide-forming systems M–C (M = Ti, Zr, Hf), an empirical relationship is proposed between the elastic stiffness constants <em>c</em><sub><em>ij</em></sub> of nonstoichiometric cubic carbides of titanium, zirconium and hafnium and their melting temperature. The dependences of the melting temperatures of nonstoichiometric cubic carbides TiC<sub><em>y</em></sub>, ZrC<sub><em>y</em></sub> and HfC<sub><em>y</em></sub> on their composition in homogeneity regions are calculated using the elastic stiffness constants <em>c</em><sub>11</sub>(<em>y</em>) and <em>c</em><sub>44</sub>(<em>y</em>) of these carbides. The calculated maximum melting temperatures are observed for carbides ∼TiC<sub>0.80</sub>, ∼ZrC<sub>0.82</sub> and ∼ HfC<sub>0.94</sub><sub>–</sub><sub>0.95</sub> and are equal to 3345, 3708 and 4192 K, respectively. There is a qualitative correlation between the concentration dependences of the melting temperatures <em>T</em><sub>m</sub>(<em>y</em>) of TiC<sub><em>y</em></sub>, ZrC<sub><em>y</em></sub> and HfC<sub><em>y</em></sub> carbides and the anisotropy of the elastic properties of these carbides.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106920"},"PeriodicalIF":4.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mining sector seeks innovation to enhance operational efficiency and prolong cutting tool life. This research investigates the impact of cryogenic treatment (CT) for 12, 24, and 36 h on tungsten carbide cutting bits used in mine machineries, focusing on its effects on cutting force, energy consumption, and tool wear during lab-scale linear rock cutting. Microstructural analysis and hardness testing follow CT, revealing improvements in hardness, the formation of new compounds, and the presence of eta carbides. Analysis of linear rock cutting experiments shows that longer holding periods under CT lead to reduced cutting force, energy consumption, and tool wear. Comparing CT 24 to untreated bit at a cutting speed of 200 m/s, CT 24 demonstrates reduction in specific energy by 39.35 %, 41.13 %, and 29.39 % at depth of cut (DoC) of 2 mm, 4 mm, and 6 mm, respectively. Additionally, CT 24 exhibits significantly lower wear rates (79.24 %, 85.44 %, and 85.01 %) compared to UT bits at the same cutting speed. Microstructural analysis identifies multiple wear mechanisms in both treated and untreated worn tools. To optimize the cutting process for mining efficiency, grey relational analysis and Python-based non-dominant sorting are employed. Grey relational analysis identifies 24-h CT, a cutting speed of 200 m/s, and a 2 mm depth of cut as optimal. Non-dominant sorting suggests 24-h CT, a cutting speed of 200 m/s, and 2–4 mm cut depth for optimal results. Pareto solutions indicate specific energy ranging from 14.96 to 9.20 kWh/m3 and wear rates ranging from 0.33 to 0.39 × 10−4 cm3/cm. Insights from this study offer valuable guidance for the mining industry to enhance cutting tool efficiency and promote environmentally sustainable mining practices.
{"title":"Next-generation tungsten carbide cutting bits through cryogenic treatment technique for superior rock cutting performance for mining applications: An experimental study","authors":"Mogana Priya Chinnasamy , Biswajit Samanta , Rahul Kumar , Rajasekar Rathanasamy","doi":"10.1016/j.ijrmhm.2024.106923","DOIUrl":"10.1016/j.ijrmhm.2024.106923","url":null,"abstract":"<div><div>The mining sector seeks innovation to enhance operational efficiency and prolong cutting tool life. This research investigates the impact of cryogenic treatment (CT) for 12, 24, and 36 h on tungsten carbide cutting bits used in mine machineries, focusing on its effects on cutting force, energy consumption, and tool wear during lab-scale linear rock cutting. Microstructural analysis and hardness testing follow CT, revealing improvements in hardness, the formation of new compounds, and the presence of eta carbides. Analysis of linear rock cutting experiments shows that longer holding periods under CT lead to reduced cutting force, energy consumption, and tool wear. Comparing CT 24 to untreated bit at a cutting speed of 200 m/s, CT 24 demonstrates reduction in specific energy by 39.35 %, 41.13 %, and 29.39 % at depth of cut (DoC) of 2 mm, 4 mm, and 6 mm, respectively. Additionally, CT 24 exhibits significantly lower wear rates (79.24 %, 85.44 %, and 85.01 %) compared to UT bits at the same cutting speed. Microstructural analysis identifies multiple wear mechanisms in both treated and untreated worn tools. To optimize the cutting process for mining efficiency, grey relational analysis and Python-based non-dominant sorting are employed. Grey relational analysis identifies 24-h CT, a cutting speed of 200 m/s, and a 2 mm depth of cut as optimal. Non-dominant sorting suggests 24-h CT, a cutting speed of 200 m/s, and 2–4 mm cut depth for optimal results. Pareto solutions indicate specific energy ranging from 14.96 to 9.20 kWh/m<sup>3</sup> and wear rates ranging from 0.33 to 0.39 × 10<sup>−4</sup> cm<sup>3</sup>/cm. Insights from this study offer valuable guidance for the mining industry to enhance cutting tool efficiency and promote environmentally sustainable mining practices.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106923"},"PeriodicalIF":4.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.ijrmhm.2024.106922
Yang Gao , Xiaoting Li , Bo-Yu Li , Sheng-Qiang Deng , De-Jian Sun , Xiao-qin Guo , Lei Fan , Linan An
In this study, a novel hot oscillating pressing (HOP) was used to prepared WC-Co cemented carbides under various oscillation frequencies. The effects of sintering frequencies on the density, microstructure, and mechanical properties of cemented carbides were systematically investigated. The results show that applying a specific oscillation frequency during the sintering process can greatly aid in the densification process, improve the uniformity of microstructure, help the grain refinement, and prevent the formation of abnormally large WC grains. The mechanical properties of the alloys showed a noticeable improvement as the oscillation frequency increased. The hardness and fracture toughness of cemented carbides were not significantly improved when the oscillation frequency was ≥5 Hz, with the optimal values reaching 1913 kg/m2 and 13.11 MPa.m1/2, in turn. The improvement in mechanical properties of cemented carbide can be mainly attributed to higher density, grain refinement, microstructure uniformity and the increase of dislocation/twins caused by plastic deformation.
{"title":"Effect of oscillation frequency on microstructure and properties of WC-Co cemented carbide prepared by hot oscillating pressing","authors":"Yang Gao , Xiaoting Li , Bo-Yu Li , Sheng-Qiang Deng , De-Jian Sun , Xiao-qin Guo , Lei Fan , Linan An","doi":"10.1016/j.ijrmhm.2024.106922","DOIUrl":"10.1016/j.ijrmhm.2024.106922","url":null,"abstract":"<div><div>In this study, a novel hot oscillating pressing (HOP) was used to prepared WC-Co cemented carbides under various oscillation frequencies. The effects of sintering frequencies on the density, microstructure, and mechanical properties of cemented carbides were systematically investigated. The results show that applying a specific oscillation frequency during the sintering process can greatly aid in the densification process, improve the uniformity of microstructure, help the grain refinement, and prevent the formation of abnormally large WC grains. The mechanical properties of the alloys showed a noticeable improvement as the oscillation frequency increased. The hardness and fracture toughness of cemented carbides were not significantly improved when the oscillation frequency was ≥5 Hz, with the optimal values reaching 1913 kg/m<sup>2</sup> and 13.11 MPa.m<sup>1/2</sup>, in turn. The improvement in mechanical properties of cemented carbide can be mainly attributed to higher density, grain refinement, microstructure uniformity and the increase of dislocation/twins caused by plastic deformation.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106922"},"PeriodicalIF":4.2,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-13DOI: 10.1016/j.ijrmhm.2024.106917
L. Ortiz-Membrado , R. Benítez , L. Llanes , E. Jiménez-Piqué
The mapping of micromechanical properties of heterogeneous materials with high-speed nanoindentation faces challenges in data interpretation and extraction of reliable phase properties. Gaussian deconvolution has commonly been used to treat this data, but problems arise when microstructures are fine compared to the indentation imprint size and the mechanical properties of the different phases are not extremely different. Recently machine-learning methods, such as clustering techniques, have emerged as good approaches to assess these challenges.
Within this context, it is important to understand the micromechanical properties of cemented carbides, materials usually referred to as hardmetals, but their complex microstructure poses challenges for assessment and interpretation. The study reveals insights from high-speed nanoindentation data treatment on hardmetals with different microstructures and binder compostion. The data has been statistically analyzed by means of a clustering method: Gaussian Mixture Model (GMM) and the fitting of a mixture of skew-normal distributions. Findings underscore the asymmetry in phase properties, and the challenges GMM encounters in some samples. The skew-normal method offers enhanced precision and addresses issues related to scatter in phase intersections, providing a more accurate representation of fine microstructural features. The combined approach of GMM and skew-normal proves consistent for reliable evaluation of micromechanical properties from nanoindentation maps in cemented carbides, and demonstrate the potential of this technique to be applied to novel hardmetal compositions as well as other composites.
{"title":"High-speed Nanoindentation Data Analysis of WC-based Cemented Carbides using Gaussian Mixture Model Clustering and Skew-normal Mixture: Beyond Gaussian Deconvolution","authors":"L. Ortiz-Membrado , R. Benítez , L. Llanes , E. Jiménez-Piqué","doi":"10.1016/j.ijrmhm.2024.106917","DOIUrl":"10.1016/j.ijrmhm.2024.106917","url":null,"abstract":"<div><div>The mapping of micromechanical properties of heterogeneous materials with high-speed nanoindentation faces challenges in data interpretation and extraction of reliable phase properties. Gaussian deconvolution has commonly been used to treat this data, but problems arise when microstructures are fine compared to the indentation imprint size and the mechanical properties of the different phases are not extremely different. Recently machine-learning methods, such as clustering techniques, have emerged as good approaches to assess these challenges.</div><div>Within this context, it is important to understand the micromechanical properties of cemented carbides, materials usually referred to as hardmetals, but their complex microstructure poses challenges for assessment and interpretation. The study reveals insights from high-speed nanoindentation data treatment on hardmetals with different microstructures and binder compostion. The data has been statistically analyzed by means of a clustering method: Gaussian Mixture Model (GMM) and the fitting of a mixture of skew-normal distributions. Findings underscore the asymmetry in phase properties, and the challenges GMM encounters in some samples. The skew-normal method offers enhanced precision and addresses issues related to scatter in phase intersections, providing a more accurate representation of fine microstructural features. The combined approach of GMM and skew-normal proves consistent for reliable evaluation of micromechanical properties from nanoindentation maps in cemented carbides, and demonstrate the potential of this technique to be applied to novel hardmetal compositions as well as other composites.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"126 ","pages":"Article 106917"},"PeriodicalIF":4.2,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142532903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silicon carbide (SiC) is an important structural ceramic material, exhibiting exceptional comprehensive properties that are unmatched by metals and other structural materials. In this study, a combination of α-SiC micron powder and β-SiC nanopowder was utilized as precursor materials for high pressure and high temperature (HPHT) sintering. Under a pressure of 5.0 GPa, polycrystalline SiC samples with mixed grain size were sintered within a temperature range from 1000 to 1700 °C, and compared with SiC samples sintered from single micron powder under identical temperature and pressure conditions. The microstructures of the two sets of SiC samples were observed using scanning electron microscopy. Additionally, the stress states and strengthening mechanisms among SiC grains with mixed grain size under HPHT were further analyzed in conjunction with X-ray diffraction results. The polycrystalline SiC composite ceramics sintered at 1700 °C exhibited superior mechanical and thermal properties, achieving a Vickers hardness of 35.2 GPa that is 23.5 % higher than that obtained by conventional spark plasma sintering and even surpassing the hardness of single crystal SiC, demonstrating thermal stability up to 1405 °C in air environment. Transmission electron microscopy was employed to analyze defects and plastic deformation in these samples. The study suggests that the primary strengthening mechanisms of the sintered polycrystalline SiC composite ceramics under HPHT include the increase in micro defects induced by in-situ plastic deformation at elevated temperatures and the effects of high-temperature creep. This study provides new insights into the HPHT sintering of hard materials.
碳化硅（SiC）是一种重要的结构陶瓷材料，具有金属和其他结构材料无法比拟的优异综合性能。本研究采用α-碳化硅微米粉末和β-碳化硅纳米粉末组合作为高压高温（HPHT）烧结的前驱体材料。在 5.0 GPa 的压力下，混合晶粒大小的多晶 SiC 样品在 1000 至 1700 °C 的温度范围内烧结，并与在相同温度和压力条件下用单微米粉末烧结的 SiC 样品进行比较。使用扫描电子显微镜观察了两组 SiC 样品的微观结构。此外，还结合 X 射线衍射结果进一步分析了混合晶粒尺寸的 SiC 晶粒在 HPHT 条件下的应力状态和强化机制。在 1700 ℃ 下烧结的多晶 SiC 复合陶瓷具有优异的机械性能和热性能，维氏硬度达到 35.2 GPa，比传统火花等离子烧结的硬度高出 23.5%，甚至超过了单晶 SiC 的硬度，在空气环境中的热稳定性可达 1405 ℃。利用透射电子显微镜分析了这些样品中的缺陷和塑性变形。研究表明，烧结多晶 SiC 复合陶瓷在 HPHT 下的主要强化机制包括高温原位塑性变形引起的微缺陷增加以及高温蠕变效应。这项研究为硬质材料的 HPHT 烧结提供了新的见解。
{"title":"Sintering polycrystalline silicon carbide composite ceramics with ultra-high hardness under high pressure","authors":"Peihong He, Yulei He, Wenjia Liang, Haidong Long, Ling Ran, Peng Yang, Fang Peng","doi":"10.1016/j.ijrmhm.2024.106918","DOIUrl":"10.1016/j.ijrmhm.2024.106918","url":null,"abstract":"<div><div>Silicon carbide (SiC) is an important structural ceramic material, exhibiting exceptional comprehensive properties that are unmatched by metals and other structural materials. In this study, a combination of α-SiC micron powder and β-SiC nanopowder was utilized as precursor materials for high pressure and high temperature (HPHT) sintering. Under a pressure of 5.0 GPa, polycrystalline SiC samples with mixed grain size were sintered within a temperature range from 1000 to 1700 °C, and compared with SiC samples sintered from single micron powder under identical temperature and pressure conditions. The microstructures of the two sets of SiC samples were observed using scanning electron microscopy. Additionally, the stress states and strengthening mechanisms among SiC grains with mixed grain size under HPHT were further analyzed in conjunction with X-ray diffraction results. The polycrystalline SiC composite ceramics sintered at 1700 °C exhibited superior mechanical and thermal properties, achieving a Vickers hardness of 35.2 GPa that is 23.5 % higher than that obtained by conventional spark plasma sintering and even surpassing the hardness of single crystal SiC, demonstrating thermal stability up to 1405 °C in air environment. Transmission electron microscopy was employed to analyze defects and plastic deformation in these samples. The study suggests that the primary strengthening mechanisms of the sintered polycrystalline SiC composite ceramics under HPHT include the increase in micro defects induced by in-situ plastic deformation at elevated temperatures and the effects of high-temperature creep. This study provides new insights into the HPHT sintering of hard materials.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106918"},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1016/j.ijrmhm.2024.106919
Jiaxuan Zhao , Jie Ning , Linjie Zhang , Gang Zhao , Shurong Li , Won-Ik Cho
Influences of the laser beam offset (LBO) on the microstructures as well as room-temperature and high-temperature mechanical properties of Ta10W/GH3030 dissimilar-material joints were investigated. In laser-welded Ta10W/GH3030 joints prepared under three conditions with LBOs of −0.2 mm (offset toward Ta10W), 0 mm, and + 0.2 mm (offset toward GH3030): the fusion zones (FZ) all contained expulsed substances Ni3Ta, NiTa, and Cr2Ta and their microhardness was certainly higher than the base metal (BM); a transition layer containing high contents of Ni3Ta, NiTa, and Cr2Ta phases was observed at the Ta10W/FZ interface. With the increase of the LBO, the contents of Ni3Ta, NiTa, and Cr2Ta in the FZ gradually declined, the average grain size in the FZ increased slightly, the microhardness of the FZ dropped rapidly, and the thickness of the transition layer at the Ta10W/FZ interface reduced obviously. Either in the room-temperature or high-temperature (750 °C) tensile tests, Ta10W/GH3030 joints were always fractured at the Ta10W/FZ interface, showing the typical brittle fracture mode, and the tensile strength of joints was enhanced with the increasing LBO. Under LBOs of −0.2, 0, and + 0.2 mm, the room-temperature tensile strengths of Ta10W/GH3030 dissimilar-material joints were 266.4, 308.6, and 341.2 MPa, while the high-temperature (750 °C) tensile strengths were 97.6, 191.5, and 202.7 MPa, respectively.
{"title":"Microstructural characteristics and mechanical properties of laser-welded Ta10W/GH3030 joints with beam offset","authors":"Jiaxuan Zhao , Jie Ning , Linjie Zhang , Gang Zhao , Shurong Li , Won-Ik Cho","doi":"10.1016/j.ijrmhm.2024.106919","DOIUrl":"10.1016/j.ijrmhm.2024.106919","url":null,"abstract":"<div><div>Influences of the laser beam offset (LBO) on the microstructures as well as room-temperature and high-temperature mechanical properties of Ta10W/GH3030 dissimilar-material joints were investigated. In laser-welded Ta10W/GH3030 joints prepared under three conditions with LBOs of −0.2 mm (offset toward Ta10W), 0 mm, and + 0.2 mm (offset toward GH3030): the fusion zones (FZ) all contained expulsed substances Ni<sub>3</sub>Ta, NiTa, and Cr<sub>2</sub>Ta and their microhardness was certainly higher than the base metal (BM); a transition layer containing high contents of Ni<sub>3</sub>Ta, NiTa, and Cr<sub>2</sub>Ta phases was observed at the Ta10W/FZ interface. With the increase of the LBO, the contents of Ni<sub>3</sub>Ta, NiTa, and Cr<sub>2</sub>Ta in the FZ gradually declined, the average grain size in the FZ increased slightly, the microhardness of the FZ dropped rapidly, and the thickness of the transition layer at the Ta10W/FZ interface reduced obviously. Either in the room-temperature or high-temperature (750 °C) tensile tests, Ta10W/GH3030 joints were always fractured at the Ta10W/FZ interface, showing the typical brittle fracture mode, and the tensile strength of joints was enhanced with the increasing LBO. Under LBOs of −0.2, 0, and + 0.2 mm, the room-temperature tensile strengths of Ta10W/GH3030 dissimilar-material joints were 266.4, 308.6, and 341.2 MPa, while the high-temperature (750 °C) tensile strengths were 97.6, 191.5, and 202.7 MPa, respectively.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"125 ","pages":"Article 106919"},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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