A Convergence Study to Determine to the Role of Pressure Solution Creep Mechanisms in Driving Cold Sintering in Functional Ceramics

冷烧结是最近引进的一种加工技术，已被证明适用于烧结大量陶瓷和陶瓷复合材料。驱动致密化的温度比世界各地陶瓷制造中使用的传统热工艺低一个数量级。实现这些极低温度的机制是利用瞬态化学相的机械化学过程。本研究考虑了推动沉积岩形成的理论和地球物理科学，并试图测试其与冷烧结工艺的相关性，该工艺目前正应用于制造先进的陶瓷材料。通过了解这些过程，可以考虑对建筑砖和砖的冷烧结产生更广泛的影响。将通过与联合国全球建筑网和非洲建筑协会的伙伴关系，示范和教育非洲农村地区当地制砖的冷烧结工艺。本科研究人员将参与该项目的工程方面。技术总结沉积岩经过多年的致密化过程被称为压力-溶液蠕变。这一过程包括压力诱导的溶解、输运和沉淀。冷烧结是一种相对较新的可持续制造工艺。本研究将涵盖岩石形成的非平衡地球物理学，并将常规烧结的致密化和晶粒生长过程联系起来。传统烧结是一种热力学过程，在比冷烧结过程高一个数量级的温度下驱动多余表面能的最小化。本文提出的研究将从实验和理论上检验对压力溶液蠕变的地球物理学理解，并考虑其对理解冷烧结致密化动力学的适用性。实现低温致密化的顺序过程包括化学-机械溶解、晶界溶解和析出，这些过程可能是速率限制步骤。提出的研究将在模型系统中访问这些现象，以便从新的基础角度更好地理解冷烧结过程，并将材料科学和地球科学结合起来。从更广泛的影响角度来看，一项调查将使用冷烧结工艺的砖形成在非洲农村地区的应用。这将涉及与全球建筑网络和非洲材料研究协会的合作。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-Technical SummaryCold sintering is a recently introduced processing technique that has been demonstrated to be applicable to sintering a broad number of ceramic and ceramic composites. The temperatures that drive densification are an order of magnitude lower than the conventional thermal processes that are used in ceramic manufacturing across the world. The mechanisms enabling these extremely low temperatures use a mechano-chemical process with the use of a transient chemical phase. This investigation considers the theories and geophysical science that drive the formation of sedimentary rock and looks to test its relevance to the cold sintering process that are now being applied to the fabrication of advanced ceramic materials. Through understanding these processes, a broader impact is considered for cold sintering of architectural bricks and tiles. Through a partnership with the United Nations Global Buildings Network and the African MRS, demonstration and education of the cold sintering processes for local brick making in rural areas in Africa will be made. Undergraduate researchers will be involved in this engineering aspect of the project.Technical SummarySedimentary rock densifies over many years with a process known as pressure solution creep. This process involves pressure induced dissolution, transport, and precipitation. Cold sintering is a relatively new introduction to a sustainable manufacturing process. This study will embrace the non-equilibrium geophysics of rock formation and correlate the densification and grain growth process of conventional sintering. Conventional sintering is a process that thermodynamically drives the minimization of excess surface energy at temperatures an order of magnitude higher than the cold sintering process. The proposed study here will experimentally and theoretically test the understanding of the geophysics of the pressure solution creep and consider its applicability to understanding the densification kinetics to cold sintering. There are various sequential processes that enable the low temperature densification including chemo-mechanical dissolution, grain boundary dissolution and precipitation and of which can be the rate limiting step. The proposed study will access these phenomena in model systems to better understand the cold sintering process from a new fundamental perspective and converging material science and geoscience. From a broader impact perspective an investigation will use the cold sintering process to the application of brick formation in rural areas of Africa. This will involve a partnership with both the Global Building Network and the African Materials Research Society.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.