激光噴丸改善高溫合金抗熱腐蝕性能試驗(yàn)研究

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摘要
高溫合金具有優(yōu)異的的耐高溫和耐腐蝕等性能，已越來越多地應(yīng)用在國(guó)防和航空領(lǐng)域。隨著航空和軍工事業(yè)的發(fā)展，對(duì)發(fā)動(dòng)機(jī)渦輪葉片材料性能的要求越來越高，激光噴丸強(qiáng)化作為革新的表面改性技術(shù)，為提高材料的強(qiáng)度、耐磨性、耐腐蝕性等提供了一種行之有效的手段。本文以IN718鎳基合金為對(duì)象，開展激光噴丸強(qiáng)化的機(jī)理及試驗(yàn)研究，并進(jìn)行相關(guān)性能的測(cè)試和表征，探討噴丸強(qiáng)化表面的熱腐蝕行為。主要工作有以下幾點(diǎn)：
介紹了激光噴丸技術(shù)的原理和特點(diǎn)，講述激光噴丸技術(shù)在國(guó)內(nèi)外的發(fā)展現(xiàn)狀；測(cè)量了激光噴丸強(qiáng)化對(duì)材料的表面質(zhì)量、微觀組織的影響，并分析其機(jī)理；基于熱腐蝕的基本理論，研究了激光噴丸改善材料熱腐蝕行為的機(jī)理。
開展了IN718 鎳基合金在常溫下不同能量的激光噴丸試驗(yàn)，采用加熱電阻爐對(duì)噴丸強(qiáng)化試樣進(jìn)行相同時(shí)間700℃、800℃和900℃溫度下的熱腐蝕試驗(yàn)，并對(duì)未噴丸試樣進(jìn)行相同條件下的熱腐蝕試驗(yàn)，對(duì)兩者試驗(yàn)前后的質(zhì)量進(jìn)行測(cè)量，算出試樣的失重和腐蝕失重率，數(shù)據(jù)顯示未噴丸試樣的腐蝕失重率是噴丸試樣的9倍左右，比較表明激光噴丸強(qiáng)化使高溫合金的抗熱腐蝕性能提高。
對(duì)腐蝕后的試樣進(jìn)行微觀組織觀察，分析噴丸和未噴丸試樣腐蝕后金相組織發(fā)現(xiàn)，未噴丸和噴丸試樣都存在腐蝕層，但未噴丸試樣的腐蝕層更明顯且組織更蓬松。
關(guān)鍵詞：激光噴丸；高溫合金；表面性能；熱腐蝕

ABSTRACT
With the excellent high temperature performance and corrosion-resistant properties,Superalloy have been increasingly used in defense and aerospace fields.With the development of aviation and military career, the material properties of the engine turbine blades have become increasingly demanding.As a innovative surface modification technology,Laser peening (LP) provide a an effective measure for the material to improve the strength, wear resistance, corrosion resistance.In this dissertation,In 718 Ni-based alloy was treated by LP and the performance of samples after LP were analyzed and characterized.Based on theoretical analysis and experimental study,the effect of LP on improving high-temperature stability and hot-corrosion resistance were studied. The principal works in this paper are as following:
Principles and characteristics of laser peening technology was introduced here.The development status at home and abroad of LP was also introduced.The effect of LP on the surface quality and microstructure of materials was measured,and analyze its mechanism.Based on the basic theory of hot corrosion, the mechanism of how LP improve the hot corrosion behavior of material.
A set of LP experiments under different power on In 718 alloy were conducted at room temperature.Resistance heating furnace used to take the hot corrosion test of the specimen under LP for the same time at different temperatures such as 700℃、800℃ and 900℃,as well as the specimen without LP.Measuring the quality of the specimen before and after the test is both needed.Then calculate the eroded quality and the corrosion weight loss rate.The corrosion weight loss rate of the the specimen without LP is much higher than the corrosion weight loss rate of the specimen under LP. So the comparison shows that the laser peening can improve the hot corrosion resistance of superalloy.
Microstructure observation were taken after the corrosion to analyze the different organizations between the specimen under LP and the specimen without LP.The corrosion layer exists both in the surface of the two kinds of the specimens,but the the corrosion layer of the specimen without LP is much more serious and the organization is much more fleeciness.
Key words:LP;superalloy;surface integrity;hot-corrosion
目錄
第一章 緒論 1
1.1 引言 1
1.2 高溫合金表面改性的研究現(xiàn)狀 3
1.3 激光噴丸強(qiáng)化技術(shù) 6
1.3.1激光噴丸強(qiáng)化技術(shù) 6
1.3.2激光噴丸強(qiáng)化技術(shù)的應(yīng)用 8
1.3.3激光噴丸強(qiáng)化技術(shù)存在的問題 9
1.4 熱腐蝕 9
1.4.1 熱腐蝕的理論 9
1.4.2 影響熱腐蝕的主要因素 10
1.4.3 熱腐蝕的研究 11
1.5 課題研究的意義和主要內(nèi)容 12
1.5.1 研究意義 12
1.5.2課題的主要研究?jī)?nèi)容 12
1.5.3研究方法、設(shè)計(jì)方案 12
第二章 激光噴丸強(qiáng)化IN718鎳基高溫合金及其熱腐蝕試驗(yàn)研究 14
2.1 激光噴丸試驗(yàn) 14
2.1.1 試樣的制備 14
2.1.2試樣儀器及裝備 15
2.1.3激光溫噴丸實(shí)驗(yàn)參數(shù)設(shè)置 16
2.1.4試驗(yàn)后處理 17
2.2熱腐蝕試驗(yàn) 18
2.2.1試樣制備 18
2.2.2試驗(yàn)方法和儀器 19
2.2.3在硫酸鹽中的熱腐蝕行為 21
2.2.4熱腐蝕后的微觀組織觀察 23
第三章 總結(jié)與展望 26
3.1總結(jié) 26
3.2展望 26
致謝 27
參考文獻(xiàn) 28