Pub Date : 2024-11-06DOI: 10.1016/j.msea.2024.147503
S.Q. Wang , Y. Zhang , G.D. Wen , J.L. Qi , Y.X. Lu
In this paper, 5 mm thick Ti-22Al-25Nb alloy plate was used for vacuum electron beam welding. The effect of TiB2 on the surface forming, macroscopic morphology, microstructure and mechanical properties of the joint was studied by optical microscope, scanning electron microscope and X-ray diffractometer. The results showed that TiB2 had an obvious effect on the microstructure and mechanical properties. The surface forming of the joint was good with the addition of TiB2, while the lower surface of the joint without the addition of TiB2 was discontinuous and presented a droplet state. The phase of WZ with TiB2 was composed of B2 phase, TiB and a small amount of O phase, while it mainly consisted of B2 phase for the joint without addition of TiB2. The hardness of the WZ with different addition of TiB2 was higher than that of the WZ without addition of TiB2. The breaking strength at high temperature of the joint without addition of TiB2 was 639 MPa, which was only 72.5 % of the BM and lower than that of the joint with different addition of TiB2.
{"title":"The microstructure and mechanical properties of electron beam welded Ti2AlNb-based alloy joint with the addition of TiB2","authors":"S.Q. Wang , Y. Zhang , G.D. Wen , J.L. Qi , Y.X. Lu","doi":"10.1016/j.msea.2024.147503","DOIUrl":"10.1016/j.msea.2024.147503","url":null,"abstract":"<div><div>In this paper, 5 mm thick Ti-22Al-25Nb alloy plate was used for vacuum electron beam welding. The effect of TiB<sub>2</sub> on the surface forming, macroscopic morphology, microstructure and mechanical properties of the joint was studied by optical microscope, scanning electron microscope and X-ray diffractometer. The results showed that TiB<sub>2</sub> had an obvious effect on the microstructure and mechanical properties. The surface forming of the joint was good with the addition of TiB<sub>2</sub>, while the lower surface of the joint without the addition of TiB<sub>2</sub> was discontinuous and presented a droplet state. The phase of WZ with TiB<sub>2</sub> was composed of B2 phase, TiB and a small amount of O phase, while it mainly consisted of B2 phase for the joint without addition of TiB<sub>2</sub>. The hardness of the WZ with different addition of TiB<sub>2</sub> was higher than that of the WZ without addition of TiB<sub>2</sub>. The breaking strength at high temperature of the joint without addition of TiB<sub>2</sub> was 639 MPa, which was only 72.5 % of the BM and lower than that of the joint with different addition of TiB<sub>2</sub>.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147503"},"PeriodicalIF":6.1,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656764","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 : 2024-11-05DOI: 10.1016/j.msea.2024.147495
Li Ye , Xu Mei , Zhen Tang , Beibei Liu , Shuo Xu , He Zheng , Jianfeng Wang , Shaokang Guan
A MXene defect engineering strategy was proposed to tailor the thermal stability of Ti3C2TX and mechanical properties of Ti3C2TX/ZK61 composites. Surface defects were introduced in the reinforcement MXene Ti3C2TX using H2O2 followed by HCl treatment, creating defects without significantly compromising its structure. MgO was induced at the grain boundary to restrain the interfacial reaction. The introduction of defects in Ti3C2TX reduced its thermal stability, leading to the decomposition of defective Ti3C2TX flakes during sintering. However, these defective Ti3C2TX flakes surrounded by MgO significantly enhanced the toughness of the Ti3C2TX/ZK61 composites. Treating Ti3C2TX with H2O2 (10 min) and HCl introduced an appropriate number of defects, resulting in a remarkable 36.1 % increase in ultimate compressive strength (UCS) and a 38.0 % enhancement in failure strain. Treating Ti3C2TX with H2O2 (20 min) and HCl introduced an excess number of defects, resulting in a 10.7 % increase in UCS and a 27.0 % enhancement in failure strain. The defective Ti3C2TX surrounded by MgO facilitated coordinated dislocation motion, alleviating local dislocation pile-up and delaying crack formation at grain boundaries. This work provides a new way to enhance the toughness of Ti3C2TX/ZK61 composites.
{"title":"MXene defect engineering for optimizing the mechanical properties of Ti3C2TX/ZK61 composites","authors":"Li Ye , Xu Mei , Zhen Tang , Beibei Liu , Shuo Xu , He Zheng , Jianfeng Wang , Shaokang Guan","doi":"10.1016/j.msea.2024.147495","DOIUrl":"10.1016/j.msea.2024.147495","url":null,"abstract":"<div><div>A MXene defect engineering strategy was proposed to tailor the thermal stability of Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> and mechanical properties of Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub>/ZK61 composites. Surface defects were introduced in the reinforcement MXene Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> using H<sub>2</sub>O<sub>2</sub> followed by HCl treatment, creating defects without significantly compromising its structure. MgO was induced at the grain boundary to restrain the interfacial reaction. The introduction of defects in Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> reduced its thermal stability, leading to the decomposition of defective Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> flakes during sintering. However, these defective Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> flakes surrounded by MgO significantly enhanced the toughness of the Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub>/ZK61 composites. Treating Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> with H<sub>2</sub>O<sub>2</sub> (10 min) and HCl introduced an appropriate number of defects, resulting in a remarkable 36.1 % increase in ultimate compressive strength (UCS) and a 38.0 % enhancement in failure strain. Treating Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> with H<sub>2</sub>O<sub>2</sub> (20 min) and HCl introduced an excess number of defects, resulting in a 10.7 % increase in UCS and a 27.0 % enhancement in failure strain. The defective Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub> surrounded by MgO facilitated coordinated dislocation motion, alleviating local dislocation pile-up and delaying crack formation at grain boundaries. This work provides a new way to enhance the toughness of Ti<sub>3</sub>C<sub>2</sub>T<sub>X</sub>/ZK61 composites.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147495"},"PeriodicalIF":6.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656767","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 : 2024-11-05DOI: 10.1016/j.msea.2024.147496
Ying Liu , Sen Zhang , Yupeng Yao , Leilei Fan , Jian Wang , Yanxia Wu , Lin Jing , Peide Han , Caili Zhang
The ideal mechanical performances of in-situ synthesized graphene/Ni composite have not been obtained due to the weak interfacial bonding. To realize the high strengthening efficiency of graphene, this paper proposed a Mo microalloying strategy. The influences of Mo concentration on the microstructures, interfacial bonding characteristics, and quasi-static tensile behavior of the composite were investigated. The results showed an appropriate Mo concentration (0.2 wt%) not only enabled a strong interfacial bonding but also reduced the stacking fault energy of the Ni matrix, generating the twinning and further altering the strength and plasticity. The yield and tensile strength of the composite were increased by 215.3 % and 20.3 %, respectively, but no significant reduction in plasticity was observed. The strengthening of the composite was ascribed to the effective load transfer, twinning, and dislocation strengthening, whereas the critical role of large-area graphene nanosheets and deformation twinning in suppressing the crack propagation ensured a high toughness.
由于界面结合力较弱，原位合成的石墨烯/镍复合材料尚未获得理想的力学性能。为了实现石墨烯的高强化效率，本文提出了一种 Mo 微合金化策略。研究了 Mo 浓度对复合材料微观结构、界面结合特性和准静态拉伸行为的影响。结果表明，适当的钼浓度（0.2 wt%）不仅能使界面结合牢固，还能降低镍基体的堆积断层能，产生孪晶，进一步改变强度和塑性。复合材料的屈服强度和拉伸强度分别提高了 215.3% 和 20.3%，但塑性没有明显降低。复合材料的强化归因于有效的载荷传递、孪晶和位错强化，而大面积石墨烯纳米片和变形孪晶在抑制裂纹扩展方面的关键作用则确保了高韧性。
{"title":"Enhancement of strength-ductility synergy of in situ synthesized graphene/Ni composite via Mo microalloying","authors":"Ying Liu , Sen Zhang , Yupeng Yao , Leilei Fan , Jian Wang , Yanxia Wu , Lin Jing , Peide Han , Caili Zhang","doi":"10.1016/j.msea.2024.147496","DOIUrl":"10.1016/j.msea.2024.147496","url":null,"abstract":"<div><div>The ideal mechanical performances of in-situ synthesized graphene/Ni composite have not been obtained due to the weak interfacial bonding. To realize the high strengthening efficiency of graphene, this paper proposed a Mo microalloying strategy. The influences of Mo concentration on the microstructures, interfacial bonding characteristics, and quasi-static tensile behavior of the composite were investigated. The results showed an appropriate Mo concentration (0.2 wt%) not only enabled a strong interfacial bonding but also reduced the stacking fault energy of the Ni matrix, generating the twinning and further altering the strength and plasticity. The yield and tensile strength of the composite were increased by 215.3 % and 20.3 %, respectively, but no significant reduction in plasticity was observed. The strengthening of the composite was ascribed to the effective load transfer, twinning, and dislocation strengthening, whereas the critical role of large-area graphene nanosheets and deformation twinning in suppressing the crack propagation ensured a high toughness.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147496"},"PeriodicalIF":6.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656760","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 : 2024-11-05DOI: 10.1016/j.msea.2024.147467
Seong-Ho Lee , Chitturi Veerendra , Hyo-Sun Jang , Geon Young Lee , Ji Hoon Kim , Jae-Hyung Cho
The recrystallization behaviors of severely cold-rolled A1050 thin sheets ( thick) with a reduction area of 98.3% were examined in detail. The thin sheets consisted of elongated and banded grain structures with typical -fiber (Brass-S-Copper) texture components. Based on electron backscatter diffraction (EBSD), microstructural features such as misorientation measures of the kernel average misorientation (KAM) and grain boundary information of the lattice misorientation angle and axis were characterized. The elongated grains with representative orientations near Copper and S components possessed slightly greater KAM values than those near Brass. During annealing, newly recrystallized grains mainly contained the representative orientations near Copper and S, as opposed to Brass. Low angle grain boundaries (LAGB) observed between the recrystallized and deformed -fiber grains revealed the occurrence of subgrain growth. The typical recrystallization Cube and Goss textures were also found during annealing. An equi-axed Cube grain growing inside deformed grains with the representative orientation near Copper reveals widespread grain boundary misorientation. An ellipsoidal Goss texture grows up along the two deformed bands with equivalent near-S orientations. One band is mainly consumed by Goss, and the other band prevents it from growing inward by means of grain boundaries with 60 . Various grain boundary misorientations reveal the dynamic evolution of the newly recrystallized grains.
详细研究了减薄面积为 98.3% 的严重冷轧 A1050 薄板（100μm 厚）的再结晶行为。这些薄板由细长的带状晶粒结构组成，具有典型的β-纤维（黄铜-S-铜）纹理成分。基于电子反向散射衍射 (EBSD)，对微观结构特征进行了表征，如核平均失向度 (KAM) 的失向测量以及晶格失向角和轴的晶界信息。铜和 S 成分附近具有代表性取向的细长晶粒的 KAM 值略大于黄铜附近的晶粒。在退火过程中，新再结晶的晶粒主要包含铜和 S 附近的代表性取向，而不是黄铜附近的代表性取向。在再结晶和变形 β 纤维晶粒之间观察到的低角度晶界 (LAGB) 显示了亚晶粒生长的发生。退火过程中还发现了典型的再结晶立方体和戈斯纹理。等轴立方体晶粒生长在变形晶粒内部，其代表取向接近铜，显示出广泛的晶界错向。一个椭圆形的 Goss 纹理沿着两个具有等效近 S 取向的变形带生长。一条变形带主要被戈斯纹理吞噬，另一条变形带则通过 60∘ 〈111〉的晶界阻止戈斯纹理向内生长。各种晶界错向揭示了新再结晶晶粒的动态演变。
{"title":"Investigation of the recrystallization behavior of cold-rolled A1050 thin sheets based on misorientation measurements and grain boundary information","authors":"Seong-Ho Lee , Chitturi Veerendra , Hyo-Sun Jang , Geon Young Lee , Ji Hoon Kim , Jae-Hyung Cho","doi":"10.1016/j.msea.2024.147467","DOIUrl":"10.1016/j.msea.2024.147467","url":null,"abstract":"<div><div>The recrystallization behaviors of severely cold-rolled A1050 thin sheets (<span><math><mrow><mn>100</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> thick) with a reduction area of 98.3% were examined in detail. The thin sheets consisted of elongated and banded grain structures with typical <span><math><mi>β</mi></math></span>-fiber (Brass-S-Copper) texture components. Based on electron backscatter diffraction (EBSD), microstructural features such as misorientation measures of the kernel average misorientation (KAM) and grain boundary information of the lattice misorientation angle and axis were characterized. The elongated grains with representative orientations near Copper and S components possessed slightly greater KAM values than those near Brass. During annealing, newly recrystallized grains mainly contained the representative orientations near Copper and S, as opposed to Brass. Low angle grain boundaries (LAGB) observed between the recrystallized and deformed <span><math><mi>β</mi></math></span>-fiber grains revealed the occurrence of subgrain growth. The typical recrystallization Cube and Goss textures were also found during annealing. An equi-axed Cube grain growing inside deformed grains with the representative orientation near Copper reveals widespread grain boundary misorientation. An ellipsoidal Goss texture grows up along the two deformed bands with equivalent near-S orientations. One band is mainly consumed by Goss, and the other band prevents it from growing inward by means of grain boundaries with 60<span><math><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span> <span><math><mrow><mo>〈</mo><mn>111</mn><mo>〉</mo></mrow></math></span>. Various grain boundary misorientations reveal the dynamic evolution of the newly recrystallized grains.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"920 ","pages":"Article 147467"},"PeriodicalIF":6.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663667","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 : 2024-11-05DOI: 10.1016/j.msea.2024.147494
Jonathan Kong , Jonathan L. McCrea , Jane Y. Howe , Uwe Erb
The effect of annealing up to 538 °C (1000 °F) on the hardness and ductility of two electrodeposited bulk nanocrystalline cobalt-phosphorus alloys (L-nCoP, 0.14 at%P and H-nCoP, 2.17 at%P) was investigated. Through a combination of electron microscopy and X-ray/synchrotron diffraction characterization, hardness and bend ductility measurements as well as density functional theory calculations, it is shown that hardness is controlled by four additive contributions. At 0.14 at%P, grain size strengthening and likely grain boundary relaxation are the dominant strengthening mechanisms. In the 2.17 at%P alloy, the contributions from solute strengthening and cobalt phosphide precursors and precipitates are much more significant and typical age strengthening behavior is observed with a peak hardness temperature of 371 °C (700 °F). The bend ductility at 0.14 at%P was in the 12–17 % range up to 482 °C (900 °F). In contrast, the ductility at 2.17 at%P decreased rapidly with increasing annealing temperatures approaching values less than 1 % at 427 °C (800 °F) due to excessive cobalt phosphide precursor and precipitate formation. The dominant deformation mechanism in both alloys was found to be basal dislocation slip.
研究了温度高达 538 °C (1000 °F)的退火对两种电沉积块状纳米钴磷合金（L-nCoP，0.14 at%P 和 H-nCoP，2.17 at%P）的硬度和延展性的影响。通过结合电子显微镜和 X 射线/同步辐射衍射表征、硬度和弯曲延展性测量以及密度泛函理论计算，结果表明硬度受四种加成作用的控制。在 0.14 at%P 时，晶粒尺寸强化和可能的晶界松弛是主要的强化机制。在 2.17 at%P 的合金中，溶质强化和磷化钴前驱体及沉淀物的作用更为显著，并出现了典型的时效强化行为，硬度峰值温度为 371 °C（700 °F）。0.14 at%P 时的弯曲延展性在 12-17% 之间，最高温度可达 482 °C (900 °F)。相反，由于磷化钴前驱体和沉淀物形成过多，2.17 at%P 时的延展性随着退火温度的升高而迅速降低，在 427 °C (800 °F) 时接近 1 %。两种合金的主要变形机制都是基底位错滑移。
{"title":"Relative hardening contributions and ductility of as-prepared and annealed nanocrystalline Co-P electrodeposits","authors":"Jonathan Kong , Jonathan L. McCrea , Jane Y. Howe , Uwe Erb","doi":"10.1016/j.msea.2024.147494","DOIUrl":"10.1016/j.msea.2024.147494","url":null,"abstract":"<div><div>The effect of annealing up to 538 °C (1000 °F) on the hardness and ductility of two electrodeposited bulk nanocrystalline cobalt-phosphorus alloys (L-nCoP, 0.14 at%P and H-nCoP, 2.17 at%P) was investigated. Through a combination of electron microscopy and X-ray/synchrotron diffraction characterization, hardness and bend ductility measurements as well as density functional theory calculations, it is shown that hardness is controlled by four additive contributions. At 0.14 at%P, grain size strengthening and likely grain boundary relaxation are the dominant strengthening mechanisms. In the 2.17 at%P alloy, the contributions from solute strengthening and cobalt phosphide precursors and precipitates are much more significant and typical age strengthening behavior is observed with a peak hardness temperature of 371 °C (700 °F). The bend ductility at 0.14 at%P was in the 12–17 % range up to 482 °C (900 °F). In contrast, the ductility at 2.17 at%P decreased rapidly with increasing annealing temperatures approaching values less than 1 % at 427 °C (800 °F) due to excessive cobalt phosphide precursor and precipitate formation. The dominant deformation mechanism in both alloys was found to be basal dislocation slip.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147494"},"PeriodicalIF":6.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656845","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}
Advanced joining technology is crucial for promoting the engineering applications of silicon carbide fiber reinforced silicon carbide matrix composites (SiCf/SiC). In this study, the (Nb0.3Ti0.7)1-xSix (x = 0.02, 0.05, 0.1, 0.15) alloy fillers were prepared by spark plasma sintering (SPS), which were used to perform short-time diffusion bonding of SiCf/SiC composites in a vacuum sintering furnace without equipment pressure. The effects of different alloy fillers and holding time on the properties of joints were systematically studied. When the Si content in the alloy filler reaches 0.10, the joining layer is the densest. This is attributed to the formation of liquid phase in the alloy filler during diffusion bonding, which promotes the densification of the joining layer. Under the conditions of 1500 °C and holding time for 30min, the SiCf/SiC composites and alloy filler undergo moderate diffusion reactions and obtain the shear strength of 52.4±7 MPa. This work helps promote the long-term application of SiCf/SiC composite joints in high temperature environments.
{"title":"Improved the mechanical properties of silicon carbide fiber reinforced silicon carbide matrix composite joints by short-time diffusion bonding with Nb-Ti-Si alloy filler","authors":"Lingzhi Chen , Chong Wei , Songbin Zhang , Xiaoqiang Li","doi":"10.1016/j.msea.2024.147492","DOIUrl":"10.1016/j.msea.2024.147492","url":null,"abstract":"<div><div>Advanced joining technology is crucial for promoting the engineering applications of silicon carbide fiber reinforced silicon carbide matrix composites (SiC<sub>f</sub>/SiC). In this study, the (Nb<sub>0.3</sub>Ti<sub>0.7</sub>)<sub>1-x</sub>Si<sub>x</sub> (x = 0.02, 0.05, 0.1, 0.15) alloy fillers were prepared by spark plasma sintering (SPS), which were used to perform short-time diffusion bonding of SiC<sub>f</sub>/SiC composites in a vacuum sintering furnace without equipment pressure. The effects of different alloy fillers and holding time on the properties of joints were systematically studied. When the Si content in the alloy filler reaches 0.10, the joining layer is the densest. This is attributed to the formation of liquid phase in the alloy filler during diffusion bonding, which promotes the densification of the joining layer. Under the conditions of 1500 °C and holding time for 30min, the SiC<sub>f</sub>/SiC composites and alloy filler undergo moderate diffusion reactions and obtain the shear strength of 52.4±7 MPa. This work helps promote the long-term application of SiC<sub>f</sub>/SiC composite joints in high temperature environments.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147492"},"PeriodicalIF":6.1,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586131","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 : 2024-11-01DOI: 10.1016/j.msea.2024.147489
D. Bajaj , R. Mehavarnam , X.F. Fang , N.S. Ma , D.Y. Li , D.L. Chen
High-strength dissimilar welded joints of AA2024-T3 alloy with an AA1230 coating and galvanized high-strength low-alloy (HSLA) steel were attained through ultrasonic spot welding (USW) in this study. The tensile lap shear failure loads over a welding energy range between 2000 J and 3000 J were observed to meet or surpass the values specified in the AWS D17.2 standard. The highest average tensile lap shear strength was obtained to be ∼169 MPa due to the formation of a ∼30–70 μm thick Al-Zn diffusion layer without the presence of intermetallic compounds. The substrate failure from the softer AA1230 coating on the AA2024 side under tensile loading and cyclic loading at higher cyclic loads was observed, which reflected a robust sticking capability. The partial failure from AA1230 coating consisted of characteristic shear dimples, allowing high plasticity upon shear deformation. While the 1000 J welds failed mainly via substrate failure from AA1230 and transverse through-thickness (TTT) cracking in AA2024, the cohesive failure across the Al-Zn diffusion layer and adhesive failure from the Al-Fe-intermetallic/Al-Zn-diffusion layer interface were observed in the welds made at 3000 J, corresponding to the superior bonding strength and longer fatigue life.
{"title":"Achieving superior aluminum-steel dissimilar joining via ultrasonic spot welding: Microstructure and fracture behavior","authors":"D. Bajaj , R. Mehavarnam , X.F. Fang , N.S. Ma , D.Y. Li , D.L. Chen","doi":"10.1016/j.msea.2024.147489","DOIUrl":"10.1016/j.msea.2024.147489","url":null,"abstract":"<div><div>High-strength dissimilar welded joints of AA2024-T3 alloy with an AA1230 coating and galvanized high-strength low-alloy (HSLA) steel were attained through ultrasonic spot welding (USW) in this study. The tensile lap shear failure loads over a welding energy range between 2000 J and 3000 J were observed to meet or surpass the values specified in the AWS D17.2 standard. The highest average tensile lap shear strength was obtained to be ∼169 MPa due to the formation of a ∼30–70 μm thick Al-Zn diffusion layer without the presence of intermetallic compounds. The substrate failure from the softer AA1230 coating on the AA2024 side under tensile loading and cyclic loading at higher cyclic loads was observed, which reflected a robust sticking capability. The partial failure from AA1230 coating consisted of characteristic shear dimples, allowing high plasticity upon shear deformation. While the 1000 J welds failed mainly via substrate failure from AA1230 and transverse through-thickness (TTT) cracking in AA2024, the cohesive failure across the Al-Zn diffusion layer and adhesive failure from the Al-Fe-intermetallic/Al-Zn-diffusion layer interface were observed in the welds made at 3000 J, corresponding to the superior bonding strength and longer fatigue life.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147489"},"PeriodicalIF":6.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To manage the structure evolution and properties formation, the external compressive and tensile loads (up to 20 MPa) were applied to CuAu alloy specimens during their ordering by cooling from 500°С at the rate of 12 deg/h. To find changes in the texture, XRD-scans and dilatometry investigations were used. Stress-strain curves obtained by tensile tests of ordered specimens were analysed. Both yield strength and strengthening rate of the specimens ordered under compressive load slightly increase. Moreover, the specimens show impressive thermal expansion at order→disorder phase transition that may be of interest for practical applications. Yield strength of the specimens ordered under tensile load decreases; however, their ultimate tensile strength and elongation to failure significantly grow. The discovered effects are explained by differences in flow mechanisms due to a change in the orientation of the domain boundaries in the specimens ordered under different load conditions. The strengthening rate of the ordered CuAu alloy is shown to be a non-monotonic dependence with its maximum near the true strain ε ≈ 0.25. A complex shape of the strengthening rate vs. true strain curves is explained by a change in the predominant deformation mode.
{"title":"Deformation behavior of the CuAu alloy ordered under external compressive or tensile load","authors":"A.Yu. Volkov , D.A. Komkova , V.A. Kazantsev , O.S. Novikova , A.M. Patselov , P.O. Podgorbunskaya , A.A. Gavrilova","doi":"10.1016/j.msea.2024.147481","DOIUrl":"10.1016/j.msea.2024.147481","url":null,"abstract":"<div><div>To manage the structure evolution and properties formation, the external compressive and tensile loads (up to 20 MPa) were applied to CuAu alloy specimens during their ordering by cooling from 500°С at the rate of 12 deg/h. To find changes in the texture, XRD-scans and dilatometry investigations were used. Stress-strain curves obtained by tensile tests of ordered specimens were analysed. Both yield strength and strengthening rate of the specimens ordered under compressive load slightly increase. Moreover, the specimens show impressive thermal expansion at order→disorder phase transition that may be of interest for practical applications. Yield strength of the specimens ordered under tensile load decreases; however, their ultimate tensile strength and elongation to failure significantly grow. The discovered effects are explained by differences in flow mechanisms due to a change in the orientation of the domain boundaries in the specimens ordered under different load conditions. The strengthening rate of the ordered CuAu alloy is shown to be a non-monotonic dependence with its maximum near the true strain <em>ε</em> ≈ 0.25. A complex shape of the strengthening rate vs. true strain curves is explained by a change in the predominant deformation mode.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"918 ","pages":"Article 147481"},"PeriodicalIF":6.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578387","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 : 2024-11-01DOI: 10.1016/j.msea.2024.147491
A. Ferrarotti , F. Giuffrida , E. Sharghivand , G. Mussino , M. Vedani , M. Baricco , A. Castellero
In this work, a mechanical and microstructural characterization of IN718 lattice structures prepared by additive manufacturing has been carried out. The goal is to investigate the link between macroscopic behaviour and microscopic properties, comparing bulk sample with lattice structures. From a mechanical point of view, all the investigated lattice structures can be classified as bending dominated. They show Ashby's coefficients CE of 3.20, 2.61 and 2.53 and Cσy of 0.42, 0.38 and 0.34, for diamond, body diagonals with rounded nodes and rhombic dodecahedron cell structures, respectively. From the microstructural analysis, crossed elongated melt-pools and mostly equiaxed grains have been observed, along the plane perpendicular to the building direction, while arc-shaped melt-pools and elongated grains have been detected on the plane parallel to the building direction. All samples were found to be slightly textured along the (100) direction. The degree of preferred orientations η, calculated from the March-Dollase coefficients extracted from the Rietveld refinement of XRD patterns, is similar for both bulk sample and lattice structures, being approximately equal to 26 % for both xy and xz sides. Calorimetric analysis detected the precipitation of secondary phases at specific temperature ranges. The presence of secondary phases has been also confirmed by the SEM micrographs showing similar precipitates. Overall, no significant difference was found between bulk samples and lattice structures in terms of grain size, grain shape, phase composition, texture, and other metallurgical properties.
{"title":"Mechanical and microstructural properties of IN718 additively manufactured lattice structures","authors":"A. Ferrarotti , F. Giuffrida , E. Sharghivand , G. Mussino , M. Vedani , M. Baricco , A. Castellero","doi":"10.1016/j.msea.2024.147491","DOIUrl":"10.1016/j.msea.2024.147491","url":null,"abstract":"<div><div>In this work, a mechanical and microstructural characterization of IN718 lattice structures prepared by additive manufacturing has been carried out. The goal is to investigate the link between macroscopic behaviour and microscopic properties, comparing bulk sample with lattice structures. From a mechanical point of view, all the investigated lattice structures can be classified as bending dominated. They show Ashby's coefficients CE of 3.20, 2.61 and 2.53 and Cσy of 0.42, 0.38 and 0.34, for diamond, body diagonals with rounded nodes and rhombic dodecahedron cell structures, respectively. From the microstructural analysis, crossed elongated melt-pools and mostly equiaxed grains have been observed, along the plane perpendicular to the building direction, while arc-shaped melt-pools and elongated grains have been detected on the plane parallel to the building direction. All samples were found to be slightly textured along the (100) direction. The degree of preferred orientations η, calculated from the March-Dollase coefficients extracted from the Rietveld refinement of XRD patterns, is similar for both bulk sample and lattice structures, being approximately equal to 26 % for both xy and xz sides. Calorimetric analysis detected the precipitation of secondary phases at specific temperature ranges. The presence of secondary phases has been also confirmed by the SEM micrographs showing similar precipitates. Overall, no significant difference was found between bulk samples and lattice structures in terms of grain size, grain shape, phase composition, texture, and other metallurgical properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147491"},"PeriodicalIF":6.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the role of the constituent phase on mechanical properties is the key strategy for achieving advanced mechanical properties in multiphase TRIP-assisted steels. This work unravels the opposing role of ferrite on tensile ductility and impact toughness in the constituent phase fraction-controlled multiphase TRIP-assisted steel. The specimens were subjected to three different intercritical annealing (IA) temperatures (775 °C, 800 °C, and 825 °C) for 20 min, and then continuously followed the bainitic isothermal transformation (BIT) at 400 °C for 30 min. With an increase in the IA temperature, the bainite fraction and the stability of retained austenite increased, accompanied by a decrease in the ferrite fraction. In-situ EBSD observation revealed the crack initiation at the deformation-induced martensite/ferrite interface. The strain localization in ferrite, assisted by transforming neighboring austenite to martensite, promoted crack initiation during the tensile test. The tensile elongation decreased from about 28 % to 17 % due to the lower strain partitioning in ferrite originating in the reduced ferrite fraction and TRIP amounts as the IA temperature increased. However, the refined grain size and the reduced ferrite fraction by a higher IA treatment improve impact toughness by about 60 % at room temperature. This study on the imbalance between tensile elongation and impact toughness sheds light on the microstructure design for advanced mechanical properties in multiphase TRIP-assisted steels.
了解成分相对机械性能的作用是在多相 TRIP 辅助钢中获得先进机械性能的关键策略。这项研究揭示了铁素体在成分相分数控制的多相 TRIP 辅助钢中对拉伸延展性和冲击韧性的相反作用。试样在三种不同的临界间退火（IA）温度（775 °C、800 °C和825 °C）下退火20分钟，然后在400 °C下持续进行贝氏体等温转变（BIT）30分钟。随着 IA 温度的升高，贝氏体部分和保留奥氏体的稳定性增加，同时铁素体部分减少。原位 EBSD 观察表明，裂纹在变形引起的马氏体/铁素体界面处产生。铁素体中的应变局部化在邻近奥氏体转变为马氏体的帮助下，促进了拉伸试验中的裂纹萌生。随着 IA 温度的升高，铁素体中的应变分区降低，铁素体分数和 TRIP 数量减少，因此拉伸伸长率从约 28% 降至 17%。然而，通过较高的 IA 处理，细化的晶粒尺寸和减少的铁素体分数可将室温下的冲击韧性提高约 60%。这项关于拉伸伸长率和冲击韧性之间不平衡的研究揭示了在多相 TRIP 辅助钢中实现先进机械性能的微观结构设计。
{"title":"Exploring the impact of intercritical annealing on microstructural evolution and mechanical performance in low alloy multiphase TRIP-assisted steels","authors":"Chang-Gon Jeong , T.T.T. Trang , Youngyun Woo , Eun Yoo Yoon , Youngseon Lee , Yoon-Uk Heo","doi":"10.1016/j.msea.2024.147490","DOIUrl":"10.1016/j.msea.2024.147490","url":null,"abstract":"<div><div>Understanding the role of the constituent phase on mechanical properties is the key strategy for achieving advanced mechanical properties in multiphase TRIP-assisted steels. This work unravels the opposing role of ferrite on tensile ductility and impact toughness in the constituent phase fraction-controlled multiphase TRIP-assisted steel. The specimens were subjected to three different intercritical annealing (IA) temperatures (775 °C, 800 °C, and 825 °C) for 20 min, and then continuously followed the bainitic isothermal transformation (BIT) at 400 °C for 30 min. With an increase in the IA temperature, the bainite fraction and the stability of retained austenite increased, accompanied by a decrease in the ferrite fraction. In-situ EBSD observation revealed the crack initiation at the deformation-induced martensite/ferrite interface. The strain localization in ferrite, assisted by transforming neighboring austenite to martensite, promoted crack initiation during the tensile test. The tensile elongation decreased from about 28 % to 17 % due to the lower strain partitioning in ferrite originating in the reduced ferrite fraction and TRIP amounts as the IA temperature increased. However, the refined grain size and the reduced ferrite fraction by a higher IA treatment improve impact toughness by about 60 % at room temperature. This study on the imbalance between tensile elongation and impact toughness sheds light on the microstructure design for advanced mechanical properties in multiphase TRIP-assisted steels.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"919 ","pages":"Article 147490"},"PeriodicalIF":6.1,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593735","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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