单合金双性能梯度功能钛合金压气机盘连续点式锻造激光快速成形研究

This project intends to produce the single titanium alloy compressor disk with double performances and functionally gradient property by using a new technology named Consecutive point-mode forging and laser rapid forming (CPF-LRF).Its innovation thoughts lie in: on the one hand, during the process of the titanium alloy compressor disk being fabricated by the technology of CPF-LRF, the equiaxed microstructure of α+β will be formed at the location of the wheel hub to meet the service demands of low temperature and high-stress and the basket-weave microstructure will also be formed at the location of the wheel rim to satisfy the work requirements of high temperature and low-stress and the functionally gradient microstructure and property will be produced between the wheel hub and the wheel rim to avoid the question of the weak link because of the significantly different microstructures and properties between the wheel hub and the wheel rim and to improve the performance of the single titanium alloy compressor disk with double microstructures and double properties, on the another hand, the intensity of stress within the disk will be effectively controlled and the precise formation of the disk will be achieved by the technology of CPF-LRF. On the basis of the deep research on the scientific questions of the critical physical metallurgy and material preparation and processing and the evolution law of the stress within the disk, the optimized technical process window of CPF-LRF forming the titanium alloy compressor disk with double performances and functionally gradient property made of single alloy will be obtained to explore a new technology of quickness, high-efficiency, low-cost and precise formation for the fabrication of the single titanium alloy compressor disk with double performances and functionally gradient property.

本项目拟采用连续点式锻造激光快速成形（CPF-LRF）新技术制造单合金双性能梯度功能钛合金压气机盘，其创新思想在于：一方面，利用CPF-LRF过程压气机盘不同部位成形阶段不同的CPF压下量和与之相适应的优化LRF工艺参数，在盘毂部位形成等轴α+β组织，满足其低温、高应力的服役要求；在盘缘部位形成网篮组织，满足其高温、低应力的工作要求;在盘毂和盘缘之间实现组织和性能梯度渐变，避免因性能突变导致过渡区域的“弱连接”，提高单合金双组织/双性能钛合金压气机盘的服役性能。另一方面，控制CPF-LRF过程压气机盘内部应力强度水平，实现钛合金压气机盘CPF-LRF的精确成形。本项目拟在深入研究CPF-LRF过程钛合金压气机盘不同部位成形阶段关键物理冶金及材料制备与加工科学问题、压气机盘内部应力演化规律的基础上，优化出CPF-LRF技术工艺窗口，为单合金双性能梯度功能钛合金压气机盘探索新的制造技术途径。

本项目研究背景：采用连续点式锻造+激光快速成形技术（Consecutive point-mode forging and Laser rapid forming ，CPF-LRF）制造单合金双性能梯度功能钛合金压气机盘，制造出低温工作轮毂为等轴细晶组织，具有优异的足够高的拉伸力学性能和低周疲劳性能；高温工作轮缘为等轴粗晶组织，具有高的持久、抗蠕变强度和优异的抗裂纹扩展能力；在轮毂和轮缘之间的过渡区域，实现组织由等轴细晶组织向等轴粗晶组织梯度转变、以及力学性能梯度过渡，避免过渡区域成为损伤、断裂的危险区域。. 本项目研究了（1）CPF-LRF TC17钛合金厚壁零件的组织和力学性能；（2）CPF-LRF Ti2AlNb厚壁零件的组织和力学性能；（3）CPF-LRF 修复TA15、TC4钛合金锻件组织和力学性能；（4）CPF-LRF修复船用DH36钢的表面组织和力学性能；（5）CPF-LRF 工艺参数对TC4钛合金厚壁零件组织和力学性能的影响；. 本项目的研究结果表明：（1）CPF-LRF的TC17、TA15、TC4钛合金和Ti2AlNb金属间化合物厚壁零件的晶粒组织均为等轴细晶组织，力学性能明显超过同种合金锻件力学性能标准；（2）CPF-LRF 修复的TA15、TC4钛合金锻件，实现了修复区和锻件基体晶粒形貌一致，且力学性能明显优于锻件本身力学性能；（3）CPF-LRF修复船用DH36钢的表面组织晶粒尺寸明显细化，耐磨性能显著提高。. 本项目的科学意义：与传统的金属零件LRF技术不同，CPF-LRF通过交替实施LRF和CPF，可制备出具有等轴细晶组织的高性能钛合金材料，因此，技术上，CPF-LRF技术明显是优于传统LRF技术的新的高性能钛合金零件成形及钛合金锻件修复增材制造技术。