Khamsepour P, Moreau C, Dolatabadi A
Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, Québec Canada.
Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON Canada.
J Therm Spray Technol. 2022;31(1-2):70-83. doi: 10.1007/s11666-021-01286-9. Epub 2021 Nov 30.
Nowadays, in the aerospace industry, additive manufacturing and repairing damaged metallic components like Ti6Al4V samples have grabbed attention. Among repairing techniques, solid-state additive manufacturing processes like cold spray are promising because of their unique benefits such as high deposition rate with almost no oxidation in the deposited materials. However, its main drawback is the level of porosity of as-sprayed samples. To increase density and inter-particle bonding, deposited particles must go through more degrees of deformation by increasing particle velocity and particle temperature. In order to increase these two parameters simultaneously, high-velocity air fuel (HVAF) can be utilized. For understanding the effect of using HVAF on particle deformation, a proper elastic-plastic finite-element-based simulation is required. The obtained outcomes show that enhancing particle velocity and providing more kinetic energy will increase particle deformation and sample density. Importantly, increasing particle temperature will seize particle deformation by thermal softening effect, i.e., enhancing as-sprayed sample density, while rising substrate temperature by preheating will soften the substrate resulting in a decrease in particle deformation.
如今，在航空航天工业中，增材制造以及修复诸如Ti6Al4V样品之类的受损金属部件已备受关注。在修复技术中，像冷喷涂这样的固态增材制造工艺很有前景，因为它们具有独特的优势，例如沉积速率高，且沉积材料几乎没有氧化。然而，其主要缺点是喷涂态样品的孔隙率水平。为了提高密度和颗粒间结合力，沉积颗粒必须通过提高颗粒速度和颗粒温度经历更多程度的变形。为了同时提高这两个参数，可以使用高速空气燃料（HVAF）。为了理解使用HVAF对颗粒变形的影响，需要进行基于弹塑性有限元的适当模拟。所得结果表明，提高颗粒速度并提供更多动能会增加颗粒变形和样品密度。重要的是，提高颗粒温度会因热软化效应而抑制颗粒变形，即提高喷涂态样品密度，而通过预热提高基体温度会使基体软化，导致颗粒变形减小。
