(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 湖南人文科技學院 材料工程系，婁底 417000)
摘 要: 利用ANSYS有限元數(shù)值模擬研究鎳基高溫合金激光近凈成形中沉積方向(單層10道(0o方向)、斜對角10道(12o方向)、單道10層(90o方向))對第一道的熱影響規(guī)律，并結(jié)合實驗對模擬結(jié)果進行進一步的驗證。結(jié)果表明：沉積單道10層對第一道的熱影響最大。隨著層(道)數(shù)增加，3個沉積方向的溫度梯度均減小，單層10道方向與斜對角10道方向減小趨勢相同；熔覆過程中第一道上中心點應力σx由壓應力逐漸轉(zhuǎn)變成拉應力，并且沉積單層10道時第一道上的拉應力數(shù)值最大。觀察鎳基合金Inconel 740成型后的組織發(fā)現(xiàn)，柱狀晶的生長方向從下到上呈外延生長特征并略偏向于材料沉積方向，與模擬結(jié)果一致。
關鍵字: 數(shù)值模擬；鎳基高溫合金；激光近凈成形
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Materials Engineering Department, Hunan University of Humanities Science and Technology, Loudi 417000, China）
Abstract:The thermal influences of deposition direction(Single layer and 10 tracks (0° direction), diagonal 10 tracks (12° direction), single track and 10 layers (90° direction)) on the first track in the laser engineered net shaping of nickel-based superalloy were studied by ANSYS finite element numerical simulation, and the simulation results were further validated by experiments. The results show that the deposition of single track and 10 layers has the greatest impact on the first track. As the number of layers (tracks) increasing, the temperature gradients in the three directions decrease, and the decrease trend of the single track and 10 layers direction is same as that of the diagonal 10 tracks direction. During the cladding process, the stress σx on the first center is gradually converted from compressive stress to tensile stress, and the maximum tensile stress is obtained on the first track when the monolayer 10 tracks is deposited. Observation of the microstructure of nickel base alloy Inconel 740 after forming indicates that the growth direction of columnar crystals is characterized by epitaxial growth from bottom to top, and slightly inclines to the direction of material deposition which is in good agreement with the simulation results.
Key words: numerical simulation; nickel based superalloy; laser engineered net shaping
