Novel Powder Metallurgy Compacts with Internal Structures

具有内部结构的新型粉末冶金压块

• 批准号: RGPIN-2015-05639
• 负责人: Doman, Darrel
• 金额: $ 1.82万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613663
• 关键词: Novel; Powder; Metallurgy; Compacts; Internal

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.

此前开发了一种新的制造技术，并申请了实用新型专利，该技术能够在两个步骤中生产完全封闭在金属中的中空部件。该技术利用粉末冶金压制和烧结技术将金属粉末致密化为完全封装内部结构的固体。这些内部结构通常由含有石蜡核的金属壳组成。首先，金属粉末被压制（“压实”）在含有软蜡填充芯的固体金属壳周围，以形成含有内部结构的金属压块或部件。随后在特定条件下加热（“烧结”）压坯允许石蜡从压坯中熔化出来，从而产生中空金属部件。 目前，主体、壳体和核心的应力状态是未知的，壳体机械故障通常由过高的压实压力引起。为了解决这个问题，将开发一个有限元模型，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，以便准确预测粉末致密化。然后将模型结果与内部结构压块的实验密度图进行比较。一旦得到验证，该模型将成为一种有价值的设计工具，因为它能够预测壳和芯材料中的应力。进一步的工作将集中在内部结构如何破坏金属粉末的常规压实的基本理解。通过获得这一基本水平的理解，将加速将该技术开发成商业产品的进展。