International Journal of Machine Tools & Manufacture最新文献

{"title":"Breaking through the bending limit of Al-alloy tubes by cryogenic effect controlled mechanical properties and friction behaviours","authors":"Hong Sun ,&nbsp;Heng Li ,&nbsp;Heng Yang ,&nbsp;Jun Ma ,&nbsp;Xuancheng Hao ,&nbsp;M.W. Fu","doi":"10.1016/j.ijmachtools.2023.104111","DOIUrl":"10.1016/j.ijmachtools.2023.104111","url":null,"abstract":"<div><p><span><span><span>Aluminium alloy (Al-alloy) tubes, especially large-diameter thin-walled tubes with a tough </span>bending radius, have been widely utilised in different industrial clusters owing to their high strength-to-weight ratio and </span>good corrosion resistance<span><span>. However, achieving such extreme specifications is challenging because severe and nonuniform bending deformation may cause tension and compression instabilities, such as overthinning, cracking, and wrinkling. Considering possible improvements in mechanical properties and friction behaviours of Al-alloy at </span>cryogenic temperature (CT), the cryogenic bending potential of the 6061-O tubes with an extreme ratio of </span></span><em>D</em>/<em>t</em><span> of 89 (diameter/wall thickness) was explored at different deformation temperatures<span><span><span>, including room temperature (RT) 20 °C, −60 °C, −120 °C, and −180 °C. First, the cryogenic mechanical properties and friction behaviour of the tubes were characterised. It was found that the overall mechanical properties of the Al-alloy tube were improved because of sub-grain formation and a more uniform distribution of dislocations at CT. The coefficient of friction between the tube and tooling exhibited a varying degree of reduction owing to the sensitivity of the tubes and the lubricant to CT. Subsequently, an innovative experimental platform for cryogenic bending was designed, and a </span>finite element model of cryogenic bending was established. Third, cryogenic tube </span>bendability and mechanism were explored. It was found that 6061-O tube formability can be effectively improved by cryogenic bending; however, there is no monotonic relationship between the bendability improvement and temperature decrease. The temperature to obtain the best bendability is −60 °C, at which the average wrinkle height is decreased by 81.4 %, and the average wall thickness reduction rate is reduced by 23.8 %. The bending limit represented by the bending radius is reduced from a 3.0</span></span><em>D</em> bending radius at RT to 1.0<em>D</em><span> at −60 °C, which is realised by the different or even opposite effects of the mechanical properties of tubes and the friction coefficient between the multiple contact interfaces on wall thinning and wrinkling.</span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"195 ","pages":"Article 104111"},"PeriodicalIF":14.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139041620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly controllable additive manufacturing of heterostructured nickel-based composites","authors":"Yu Kong ,&nbsp;Kaiyuan Peng ,&nbsp;Haihong Huang","doi":"10.1016/j.ijmachtools.2023.104112","DOIUrl":"10.1016/j.ijmachtools.2023.104112","url":null,"abstract":"<div><p>Owing to hetero-deformation induced (HDI) strengthening and HDI work hardening, heterostructured materials with both “hard” and “soft” features have been proven to achieve strength–ductility synergy. Laser-directed energy deposition (LDED) has shown tremendous potential in the fabrication of heterostructured materials, but faces challenges in accurately placing the required structures or materials at specific times and locations. This study developed a novel Ti₂<span>AlC (MAX phase)-modified Inconel<span> 718 composite material (MAX/Inconel 718) with multiscale precipitation (γ’, carbides, Laves phase) characteristics during solidification, highly sensitive to changes in cooling rates, and exhibiting excellent controllability of strength. A method called multibeam diameter laser-directed energy deposition (MBD-LDED), which allows the dynamic adjustment of the beam diameter during the building process to alter the cooling rate during solidification, is proposed. This enabled the placement of MAX/Inconel 718 with different strengths at suitable positions within the part. Different combinations of beam diameters can form periodic distributions and spatial interlocking structures with alternating “soft” and “hard” features perpendicular and parallel to the building direction. Compared to commercial Inconel 718, MAX/Inconel 718 demonstrated excellent manufacturability, strength, and high-temperature oxidation resistance. This study provides new insights into the design and performance optimisation of heterostructures using homogeneous materials and offers guidance for the integrated manufacturing of heterostructured components in the context of comprehensive material–structure–performance design.</span></span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"195 ","pages":"Article 104112"},"PeriodicalIF":14.0,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138943502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving superelastic shape recoverability in smart flexible CuAlMn metamaterials via 3D printing","authors":"Dan Zheng ,&nbsp;Ruidi Li ,&nbsp;Jingtao Kang ,&nbsp;Mengjie Luo ,&nbsp;Tiechui Yuan ,&nbsp;Changjun Han","doi":"10.1016/j.ijmachtools.2023.104110","DOIUrl":"10.1016/j.ijmachtools.2023.104110","url":null,"abstract":"<div><p><span><span><span>Despite the remarkable advancements in the additive manufacturing<span> of metamaterials, tradeoffs remain between functionality and mechanical performance owning to static configuration, which limits their application, particularly in areas that require efficient </span></span>multifunctionality. In this paper, we present a novel approach for fabricating multifunctional smart flexible metal metamaterials using laser </span>powder bed fusion<span><span> technology. This approach enables the reversible recovery superelastic strain exceeding 20 % with a 100 % recovery rate—ten times higher than that observed in the printed alloy. This is achieved by utilising an innovative metamaterial structural design and a novel shape memory alloy powder. To achieve the aforementioned purpose, the metamaterial unit cells were initially designed to ensure flexible deformation ability with a </span>Poisson's ratio<span> of zero. Then, we prepared a novel shape memory alloy composition of Cu-18at%Al-l0at%Mn-0.3 at%Si, which exhibited excellent printability and adaptability within the laser powder bed fusion additive manufacturing process. Additionally</span></span></span><strong>,</strong><span><span> the printed SMA exhibited superelasticity, one-way and two-way shape memory effect under varying parameters. Furthermore, the combination of multifunctionality into the flexible CuAlMn metamaterials was achieved by manipulating process parameters. Remarkably, the printed metamaterial demonstrates exceptional flexibility deformation, and presents superelasticity or shape memory effect, ensuring the recovery of its original shape after experiencing deformation. This work not only demonstrates the vast potential of utilising </span>additive manufacturing technology for fabricating functional and adaptable metal metamaterials but also presents an innovative approach for creating smart metal metamaterial.</span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"195 ","pages":"Article 104110"},"PeriodicalIF":14.0,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138770241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Additive manufacture of ultrasoft bioinspired metamaterials","authors":"Zhenyang Gao ,&nbsp;Pengyuan Ren ,&nbsp;Hongze Wang ,&nbsp;Zijue Tang ,&nbsp;Yi Wu ,&nbsp;Haowei Wang","doi":"10.1016/j.ijmachtools.2023.104101","DOIUrl":"10.1016/j.ijmachtools.2023.104101","url":null,"abstract":"<div><p><span>The dynamic loading behavior of materials plays a vital role in various engineering applications, such as aerospace protective components, armor, marine infrastructures, and automotive crash safety. The advent of </span>additive manufacturing technologies<span> has enabled the design of metamaterials that exhibit exceptional mechanical performance and artificially engineered properties not found in nature. However, fabricating ideal materials that resist dynamic loading is challenging because of the complexity of dynamic mechanical processes and varying requirements across different applications. In this study, a novel hierarchical design is proposed that combines natural fiber-inspired frameworks with graphene-inspired parent structures. This design aims to produce metamaterials, with characteristics such as reduced dynamic compressive strength<span>, high energy absorption, and programmable dynamic loading, via advanced manufacturing technologies<span>. An additive-manufacturing-oriented digital design approach and machine learning techniques<span> were employed to engineer the dynamic loading performance of graphene-inspired metamaterials using the bonding principles inspired by natural fibers, to facilitate the design of next-generation metamaterial for advanced manufacturing. Experimental results illustrate the significant improvements achieved with our metamaterials compared to their existing counterparts. These improvements include a decrease in dynamic compressive strength of up to 86 %, while maintaining a remarkable 682 % enhancement in energy absorption during dynamic compressions, with a 42 % reduction in the energy decay rate. A compositional design strategy and programmable dynamic compression curve methodology is proposed that enable the tailored optimization of dynamic loading behaviors without modifying the base topology of metamaterials. This research offers a promising pathway for the development of next-generation materials, engineered to withstand dynamic loadings with intelligent and programmable performances suitable for aerospace, defense, and other high-value applications. By leveraging the advantages of natural fiber-inspired structures and graphene-inspired metamaterials, this work contributes to the advancement of materials with tailored resistance to dynamic loading and opens new possibilities for intelligent dynamic loading performance.</span></span></span></span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"195 ","pages":"Article 104101"},"PeriodicalIF":14.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138475907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instantaneous formation of covalently bonded diamond–graphite–graphene with synergistic properties","authors":"Bo Yan ,&nbsp;Ni Chen ,&nbsp;Yan Zhu ,&nbsp;Yinfei Yang ,&nbsp;Guolong Zhao ,&nbsp;Wei Zhao ,&nbsp;Xiuqing Hao ,&nbsp;Liang Li ,&nbsp;Lei Wang ,&nbsp;Eberhard Abele ,&nbsp;Ning He","doi":"10.1016/j.ijmachtools.2023.104087","DOIUrl":"10.1016/j.ijmachtools.2023.104087","url":null,"abstract":"<div><p><span>Diamond and graphene are the most widely used carbon allotropes and offer great potential for developing mechanical, electronic, energy-storage, and sensor applications. Their combination, especially interfacial covalent bonding, can impart excellent properties. However, achieving interfacial covalent bonding with superior performance using flexible and low-power strategies remains challenging. This study developed a novel instantaneous transformation method from diamond to graphene to prepare a new covalent structure of diamond–nano-graphite–graphene (CDGG). That is, a nanosecond-pulse laser induces sp</span>³-to-sp²<span><span> instantaneous transformations from diamond to graphite in air, and the subsequent mechanical cleavage overcomes the weak van der Waals forces to achieve the final transformation of graphite to graphene. First, the key factors influencing laser-induced graphitization and mechanical cleavage were investigated, and a covalent carbon structure with multidirectional graphene was obtained. Furthermore, the mechanisms encompassing the lattice transformation, interface relationships, transformation time, and interface bonding were elucidated. The obtained new structure synergized the excellent properties of diamond, nano-graphite, and graphene, exhibiting superior </span>lubrication<span><span>, mechanochemical wear resistance, durability, and load-capacity. Compared to polished diamond, the obtained structure exhibited a significant decrease in the stable coefficient of friction by 49–59 % and a reduction of more than one order of magnitude in the relative wear rate under high friction against </span>ferrous metals with a normal load of 1–9 N. Even under a heavy load of 100 N, it still exhibited superior lubrication and mechanochemical wear resistance. Finally, the preparation and patterning of covalent carbon structures were achieved on various diamond surfaces with high efficiency, environmental friendliness, and low power. This study is expected to broaden the scope of developing and applying diamond, diamond films, and graphene devices.</span></span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104087"},"PeriodicalIF":14.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91992427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient post-processing of additive manufactured maraging steel enhanced by the mechanochemical effect","authors":"Yuchao Bai ,&nbsp;Yan Jin Lee ,&nbsp;Yunfa Guo ,&nbsp;Qi Yan ,&nbsp;Cuiling Zhao ,&nbsp;A. Senthil Kumar ,&nbsp;Jun Min Xue ,&nbsp;Hao Wang","doi":"10.1016/j.ijmachtools.2023.104086","DOIUrl":"10.1016/j.ijmachtools.2023.104086","url":null,"abstract":"<div><p>Additive manufacturing technologies<span><span><span><span> are beginning to shift toward hybridization with subtractive processes and it is vital to identify techniques that can enhance the machinability of the difficult-to-cut additively manufactured metals and offer easy integration. The mechanochemical effect, which can be induced by surfactant, is a feasible solution for hybrid integration due to the beneficial enhancements to the cutting performance, online </span>integrability, and negligible impact on the </span>AM process<span> as compared to cutting fluids, cryogenic cutting, etc. To realize the successful integration of the mechanochemical effect and hybrid additive/subtractive manufacturing, micro-cutting of AMed high-strength maraging steel<span><span> was performed to study the relationship between microstructural features, mechanical properties, cutting performance and effectiveness of the mechanochemical effect. The results show that the mechanochemical effect was successfully induced in the as-built and solution-treated steels by inhibiting </span>dislocation movement to induce the </span></span></span>embrittlement<span> of chip surface and strain localization<span> within the chip, thereby leading to substantial reductions in cutting forces of up to 35.24 % and 53.09 %, respectively, with significant improvement in the machined surface quality. However, the presence of 7.7 nm nanoparticles in the age-treated steels renders the mechanochemical effect ineffective in improving machinability. The nanoparticles sharply increased the strength, hardness, and brittleness of the AMed maraging steel where the brittleness replaced the role of surfactant that suppressed plasticity in the chip free surface. The notion was affirmed by the similarities between the cutting chips of the brittle aged steel without surfactant and the as-built steel with surfactant. This study systematically revealed the underlying mechanism of inducing the mechanochemical effect during the micro-cutting of AMed high-strength materials with different microstructures and mechanical properties. More importantly, it is evident that the mechanochemical effect is a highly feasible solution for enhanced hybrid manufacturing, especially for robot-based fabrication works that involve high degrees of freedom and large working ranges but are limited by low mechanical stiffness.</span></span></span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104086"},"PeriodicalIF":14.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49870642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards understanding the crack suppression mechanism in brittle materials with high grinding speed at different temperatures","authors":"Jianqiu Zhang ,&nbsp;Xuekun Shang ,&nbsp;BinBin He ,&nbsp;Bi Zhang","doi":"10.1016/j.ijmachtools.2023.104088","DOIUrl":"10.1016/j.ijmachtools.2023.104088","url":null,"abstract":"<div><p><span>Ductile-regime grinding has been used to eliminate the formation of subsurface cracks by setting an extremely small depth of cut (DOC). The critical DOC is affected by multiple factors, including the grinding speed and material temperature. The underlying mechanism of DOC affected by the grinding speed is still unclear. To reveal the role of grinding speed and material temperature during the formation of cracks, we conducted a series of single-point grinding experiments with the different grinding speeds (26.7–192.3 m/s) and the initial material temperatures (25–200 </span><span><math><mrow><mo>°C</mo></mrow></math></span><span><span>). The experimental results showed that cracks were suppressed with an increase in the grinding speed and initial material temperature even when the DOC was much deeper than the critical DOC determined by the ductile-regime grinding. To understand the mechanisms underlying crack nucleation and suppression, we conducted systematic molecular dynamics simulations. Both simulation and experimental results showed that a crack can be formed by a single slip band. The crack nucleates from a microvoid within the slip band. With the aid of the local tensile stress on one side of the slip band tip, the crack nucleation forms an opening crack. The crack suppression is primarily caused by the high‐pressure field during high‐speed grinding, where the high‐pressure field superposes the local tensile stress to forming a </span>compressive stress state that prevents crack nucleation. In addition, the brittle‐ductile transition is induced by the high temperature on the surface during high‐speed grinding. This study provides insights into building the DOC criterion for different grinding speeds and temperatures based on a ‘bottom-up’ approach.</span></p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104088"},"PeriodicalIF":14.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134656367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ experimental and high-fidelity modeling tools to advance understanding of metal additive manufacturing","authors":"Lu Wang ,&nbsp;Qilin Guo ,&nbsp;Lianyi Chen ,&nbsp;Wentao Yan","doi":"10.1016/j.ijmachtools.2023.104077","DOIUrl":"10.1016/j.ijmachtools.2023.104077","url":null,"abstract":"<div><p>Metal additive manufacturing has seen extensive research and rapidly growing applications for its high precision, efficiency, flexibility, etc. However, the appealing advantages are still far from being fully exploited, and the bottleneck problems essentially originate from the incomplete understanding of the complex physical mechanisms spanning from the manufacturing processes, microstructure evolutions, to mechanical properties. Specifically, for powder-fusion-based additive manufacturing such as laser powder bed fusion, the manufacturing process involves powder dynamics, heat transfer, phase transitions (melting, solidification, evaporation, and condensation), fluid flow (gas, vapor, and molten metal liquid), and their interactions. These interactions induce not only various defects but also complex thermal-mechanical-compositional conditions. These transient conditions lead to highly non-equilibrium microstructure evolutions, and the resultant microstructures, together with those defects, can significantly alter the mechanical properties of the as-built parts, including strength, ductility and residual stress. We believe that the most efficient approach to advance the fundamental understanding is integrating <em>in-situ</em> experimentation and high-fidelity modeling. In this review, we summarize the state of the art of these two powerful tools: <em>in-situ</em> synchrotron experimentation and high-fidelity modeling, and provide an outlook for potential research directions.</p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104077"},"PeriodicalIF":14.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0890695523000858/pdfft?md5=ade9a847d0cb113f4720405c265ab583&pid=1-s2.0-S0890695523000858-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49833034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving material diversity in wire arc additive manufacturing: Leaping from alloys to composites via wire innovation","authors":"Hao Yi ,&nbsp;Le Jia ,&nbsp;Jialuo Ding ,&nbsp;Huijun Li","doi":"10.1016/j.ijmachtools.2023.104103","DOIUrl":"10.1016/j.ijmachtools.2023.104103","url":null,"abstract":"<div><p>Multi-material components featuring high performance and design flexibility have attracted considerable attention, providing solutions to meet the performance demands of high-end equipment components. Achieving material diversity in additive manufacturing (AM) is a fundamental step towards manufacturing multi-material components. Wire arc additive manufacturing (WAAM), an important branch of AM technology, boasts notable advantages in the efficient and customized preparation of large-scale parts due to its high deposition efficiency and unrestricted forming size. However, achieving material diversity in WAAM, constrained by its reliance on wire-form raw materials, has emerged as a compelling challenge. Wire innovation, including multiple, stranded, and cored wires, have furnished solutions to this challenge. To this end, this review provides an overview of the current developments in WAAM via wire innovation and suggests future research directions, aiming to serve as a reference for the further advancement of WAAM. Initially, the article introduces several WAAM printing forms, their manufacturing features, printable materials and inherent manufacturing limitations, and the intermixing of metal constituents of WAAM, prior to highlighting the advantages and necessity of achieving material diversity. Subsequently, the exposition of multi-wire-arc AM demonstrates its utility in the preparation of binary or ternary alloys, inclusive of intermetallic compounds and functionally graded materials, responding adeptly to the deficiencies of conventional WAAM, which is limited to single-material printing. The merits and progression of stranded-wire-arc AM for high-entropy alloy production are synthesized and debated, especially given that creating components with multiple metal elements via multi-wire-arc AM customarily confronts the constraint of necessitating more intricate manufacturing equipment and processes. Further, the review explores the recently developed cored-wire-arc AM technology, which actualizes the manufacturing of composite materials, amalgamating metals and non-metals, to remedy the issues encountered with standard WAAM, incapable of realizing non-metallic material printing. Considering machine tools as an important means to achieve material diversity in WAAM, we expand on the current machine tool architecture and its corresponding design tools. Finally, the current research status on WAAM via wire innovation is summarized and potential future research directions are proposed.</p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104103"},"PeriodicalIF":14.0,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0890695523001116/pdfft?md5=436c706cacd759bb73babc38df99f6d3&pid=1-s2.0-S0890695523001116-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138450080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating reversion ageing and forming of high-strength Al alloys: Principles and theoretical basis","authors":"Chunhui Liu ,&nbsp;Jun He ,&nbsp;Zhuangzhuang Feng ,&nbsp;Peipei Ma ,&nbsp;Lihua Zhan","doi":"10.1016/j.ijmachtools.2023.104091","DOIUrl":"10.1016/j.ijmachtools.2023.104091","url":null,"abstract":"<div><p>Simultaneously improving the formability and post-formed strength of high-strength aluminum (Al) alloys, such as Al–Zn–Mg–Cu alloys, is essential in manufacturing complex-shaped panel components. The strict requirements on heat-treatment condition and high tooling costs limit the applications of current forming methods. A novel process called integrated reversion ageing and forming (IRAF) is proposed to form naturally aged (NA or T4 tempered) Al alloys. A principle-based concept analysis and systematic thermo-mechanical-metallurgical study of the IRAF process were performed. Additionally, tensile tests were conducted to evaluate the effects of parameters including heating rate, holding time, and forming temperature on formability and baked strength. The deformability of the AA7075-T4 alloy can be significantly enhanced through rapid heating to the reversion ageing temperature (150–300 °C), followed by short-term holding, as evidenced by the reduced yield strength of 200 MPa and increased uniform ductility. An instant strength increase to a value close to that of the T6 state was obtained after a short bake hardening (BH) treatment. Further, temperature-time-property (TTP) diagrams were established based on the correlation between the measured mechanical properties and through-process microstructure evolution to explain the mechanism underlying the optimised processing window of IRAF. The results indicate that fast-heating rate (&gt;300 °C/min) promotes the reversion of NA clusters and inhibits re-precipitation of solutes, thereby improving the warm formability. Reversion ageing above 240 °C could induce the formation of coarse η'/η phases, leading to a considerably declined BH response. To accurately predict the strength evolution and deformation behavior during IRAF, a physical-based unified constitutive model was constructed by considering the reversion of NA clusters and solute re-precipitation. The bending and drawing tests on the AA7075-T4 alloy sheets verified that IRAF in the most-reverted state enabled optimum formability. The findings inspire promoting the reversion of pre-existing metastable particles to improve warm formability and post-formed age hardening.</p></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"194 ","pages":"Article 104091"},"PeriodicalIF":14.0,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0890695523000998/pdfft?md5=7ab5eef26e0e5a07b7254bd2fa320817&pid=1-s2.0-S0890695523000998-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138438963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}