Novel Powder Metallurgy Compacts with Internal Structures

之前开发了一种新的制造技术，并申请了实用新型专利，该技术可以仅用两步就能生产出完全封闭在金属中的空心部件。该技术利用粉末冶金压制烧结技术，将金属粉末致密成一个完全封装内部结构的固体体。这些内部结构通常由含有石蜡芯的金属壳组成。首先，将金属粉末压紧（“压实”）在包含软蜡填充核心的固体金属外壳周围，形成包含内部结构的金属压块或部件。在特定条件下对压坯进行后续加热（“烧结”），使石蜡从压坯中熔化，从而产生空心金属部件。******目前，主体、壳体和核心的应力状态是未知的，壳体的机械故障通常是由于过高的压实压力造成的。为了解决这个问题，将开发一个有限元模型来模拟金属石蜡芯内部结构的压实。该模型将采用金属粉末和蜡芯的非线性材料模型，以便准确预测粉末密度。然后将模型结果与内部结构压实体的实验密度图进行比较。一旦得到验证，该模型将成为一个有价值的设计工具，因为它能够预测壳和芯材料的应力。进一步的工作将集中在对内部结构如何破坏金属粉末常规压实的基本理解上。通过获得这种基本的理解，将技术发展为商用产品的进程将会加快

A novel manufacturing technology was previously developed, with a utility patent applied for, which is capable of producing a hollow component in only two steps that is completely enclosed in metal. The technology leverages the powder metallurgy press-and-sinter technique to densify metal powder into a solid body completely encapsulating an internal structure. These internal structures most often are composed of a metallic shell containing a paraffin wax core. Firstly, metal powder is pressed ("compacted") around a solid metal shell containing a soft wax-filled core to form a metal compact or part containing an internal structure. Subsequent heating ("sintering") of the compact at particular conditions allows for the paraffin to melt out of the compact, thus producing a hollow metal part.******Currently, the stress state of the body, shell, and core is unknown and shell mechanical failures often result from overly high compaction pressures. To address this, a finite element model will be developed which simulates the compaction of a metal, paraffin-core internal structure. The model will employ nonlinear material models for both the metal powder and wax core to allow for an accurate prediction of the powder densification. The model results will then compared against experimental density maps of internal structure compacts. Once validated, this model will become a valuable design tool as it is capable of predicting the stress in both the shell and core materials. Further work will focus on the fundamental understanding of how the internal structure disrupts the conventional compaction of the metal powder. By gaining this fundamental level of understanding, progress towards developing the technology into a commercial-ready product will be accelerated.**