Sintered metals serving as thermal interface materials (TIMs) with superior thermal conductivities show the most promise in meeting the heat dissipation requirements of next-generation wide bandgap applications. Nevertheless, their thermal stabilities during high-temperature service provide significant challenges. Herein, a facile approach was developed for one-step synthesis of single-phase Ag-Cu supersaturated solid-solution nanoparticle (Ag-Cu SS-NP) pastes with adjustable Cu contents (up to 37.7 at.%), and they exhibited ultrahigh resistance to oxidation and excellent sinterability. A paste composed of Ag-Cu SS-NPs was sintered in air at 250 °C for 20 min, and this resulted in a dense supersaturated structure with an impressive thermal conductivity of 157.8 W/(m·K) and a room-temperature shear strength of 133.4 MPa. Microstructural analyses demonstrated that Cu had precipitated from the Ag lattice to form Cu nanoprecipitates, which refined the grain sizes and induced high-density dislocations during sintering. For the pinning effect of dislocations and grain boundaries by the Cu nanoprecipitates and coherent twins, the high-temperature (400 °C) shear strength of sintered Ag-Cu SS-NP joints was significantly improved by 67% (58.6 MPa), meanwhile the shear strength after long-term aging at 200 and 300°C for 960 h were increased by 123% (140.3 MPa) and 80% (82.4 MPa) compared to those of sintered Ag NP joints, respectively. The remarkable thermal stability is far superior to traditional TIMs, so the Ag-Cu SS-NP paste exhibits excellent potential as a TIM for high-temperature power device applications.

烧结金属作为热界面材料（TIM），具有优异的导热性，最有希望满足下一代宽带隙应用的散热要求。然而，它们在高温使用期间的热稳定性提出了重大挑战。在此，开发了一种简便的方法，用于一步合成具有可调 Cu 含量（高达 37.7 at.%）的单相 Ag-Cu 过饱和固溶体纳米颗粒（Ag-Cu SS-NP）浆料，并且它们表现出超高的性能。抗氧化性和优异的烧结性。由 Ag-Cu SS-NPs 组成的糊剂在空气中于 250 °C 下烧结 20 分钟，形成致密的过饱和结构，具有 157.8 W/(m·K) 的令人印象深刻的导热率和室温剪切力强度为133.4兆帕。微观结构分析表明，Cu 从 Ag 晶格中析出，形成 Cu 纳米沉淀物，细化了晶粒尺寸并在烧结过程中引起高密度位错。由于Cu纳米沉淀物和共格孪晶对位错和晶界的钉扎效应，烧结Ag-Cu SS-NP接头的高温（400℃）剪切强度显着提高了67%（58.6 MPa），同时与烧结Ag NP接头相比，在200和300℃长期时效960 h后的剪切强度分别提高了123%（140.3 MPa）和80%（82.4 MPa）。卓越的热稳定性远远优于传统的 TIM，因此 Ag-Cu SS-NP 浆料作为高温功率器件应用的 TIM 展现出巨大的潜力。