本文選題：溫度場 + 應力場　； 參考：《沈陽航空航天大學》2015年碩士論文

【摘要】：激光沉積修復技術(Laser Deposition Repairing Technology)是將激光快速成形技術與激光熔覆技術相結合起來發(fā)展的一種先進的增材制造技術,該技術可以修復任意復雜形狀零件存在的損傷及制造缺陷。但激光沉積修復過程伴隨復雜的熱力變化,很難進行試驗檢測研究,并且修復后零件存在變形開裂問題,零件表面及內(nèi)部存在很大的殘余應力,嚴重的影響激光沉積修復的零件修復質(zhì)量,一但修復區(qū)開裂,產(chǎn)生修復廢品,修復過程被迫終止�；诖�,本文對激光沉積修復TA15鈦合金溫度場及應力場進行了研究,為控制激光沉積修復過程中殘余應力及變形提供理論依據(jù)。本文采用ANSYS有限元分析軟件,建立了激光沉積修復過程溫度場及應力場的數(shù)學模型。采用單元生死技術實現(xiàn)對激光沉積修復TA15鈦合金溫度場的數(shù)值模擬,研究了激光功率、掃描速度等工藝參數(shù)以及不同基材大小和分區(qū)域掃描對激光沉積修復溫度場的影響規(guī)律,分析了修復件內(nèi)部節(jié)點的熱循環(huán)特點以及溫度梯度分布規(guī)律。在溫度場模擬的基礎上,采用熱力耦合的方法,對應力場進行了數(shù)值模擬,分析了工藝參數(shù)及不同掃描方式及修復基體預先加熱對激光沉積修復應力場的影響。搭建了激光沉積修復實驗系統(tǒng),采用紅外測溫儀對激光沉積修復過程溫度場進行了實時動態(tài)跟蹤測量,對激光沉積修復組織進行分析,最后對修復表面殘余應力進行了測量。通過以上試驗對模擬結果進行了驗證,進一步完善了數(shù)學模型,為提高修復質(zhì)量提供參考依據(jù)。
[Abstract]:Laser Deposition Repairing Technology) is a kind of advanced material augmentation technology which combines laser rapid prototyping technology with laser cladding technology. This technology can repair the damage and manufacturing defects of parts with any complex shape. However, the process of laser deposition repair is accompanied by complex thermal changes, so it is difficult to carry out experimental detection and research, and there are deformation and cracking problems in the parts after repair, and there are large residual stresses on the surface and inside of the parts. Seriously affect the repair quality of laser deposition repair parts, but the repair area cracks, resulting in repair scrap, the repair process has to be terminated. Based on this, the temperature field and stress field of TA15 titanium alloy repaired by laser deposition are studied, which provides a theoretical basis for controlling residual stress and deformation during laser deposition and repair. In this paper, the mathematical model of temperature field and stress field in laser deposition repair process is established by using ANSYS finite element analysis software. The numerical simulation of temperature field of laser deposition and repair of TA15 titanium alloy was carried out by using element birth and death technique. The influence of laser power, scanning speed and different substrate size and area scanning on the temperature field of laser deposition repair was studied. The characteristics of thermal cycling and the temperature gradient distribution of the joints are analyzed. Based on the simulation of temperature field, the thermal coupling method is used to simulate the stress field of laser deposition. The effects of process parameters, different scanning methods and pre-heating of repair matrix on the stress field of laser deposition repair are analyzed. The experimental system of laser deposition repair was set up. The temperature field of laser deposition repair process was measured by infrared thermometer, and the microstructure of laser deposition repair was analyzed. Finally, the residual stress of the surface was measured. The simulation results are verified by the above experiments, the mathematical model is further improved, and the reference is provided for improving the repair quality.
【學位授予單位】：沈陽航空航天大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TG665

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本文編號：1963643