發(fā)布時(shí)間：2018-01-07 03:11

  本文關(guān)鍵詞：激光沖擊強(qiáng)化TC11鈦合金高溫摩擦磨損性能研究　出處：《江蘇大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： 激光沖擊 TC11鈦合金 高溫 磨損機(jī)理 摩擦系數(shù)

【摘要】：激光沖擊強(qiáng)化(laser shock peening,LSP)利用誘導(dǎo)產(chǎn)生的高壓、瞬時(shí)等離子體沖擊波實(shí)現(xiàn)對(duì)材料改性,可以有效提高材料的耐磨性。本文研究了TC11鈦合金在不同激光沖擊工藝參數(shù)以及不同環(huán)境下的磨損行為和磨損性能變化。采用SEM、EDS等對(duì)磨痕表面和截面的形貌、成分和結(jié)構(gòu)等進(jìn)行了分析,探討了TC11鈦合金激光沖擊前后的主要磨損形式,分析了激光沖擊強(qiáng)化提升TC11高溫下耐磨性的機(jī)制,為開(kāi)展高溫環(huán)境下鈦合金摩擦磨損性能的研究奠定了理論基礎(chǔ)。論文的主要研究?jī)?nèi)容和結(jié)論如下:(1)激光沖擊工藝參數(shù)對(duì)TC11鈦合金摩擦性能有較大影響,隨著激光沖擊層數(shù)的增加摩擦系數(shù)達(dá)到穩(wěn)定的時(shí)間越短,光斑搭接率為50%時(shí)摩擦系數(shù)較大。激光沖擊試樣的摩擦系數(shù)隨著溫度的升高逐漸減小并且波動(dòng)性較小。激光沖擊前后試樣的摩擦系數(shù)均隨著載荷的增加呈現(xiàn)逐漸增加的趨勢(shì)。(2)激光沖擊強(qiáng)化技術(shù)可以顯著提高TC11鈦合金的耐磨性能。鈦合金高溫環(huán)境下的耐磨性隨著激光沖擊層數(shù)的增加而逐漸提高。600°C及以下,TC11鈦合金經(jīng)過(guò)激光沖擊后,其耐磨性隨著溫度的升高而增強(qiáng),而未沖擊試樣的耐磨性隨著溫度升高先升高后下降。25N及以下,激光沖擊前后鈦合金的磨損率均隨著載荷的增大而增大,然而經(jīng)激光沖擊后試樣的磨損率較小。(3)未沖擊試樣的磨痕表面出現(xiàn)許多裂紋,磨屑呈現(xiàn)大塊剝落,其主要磨損機(jī)制為剝層磨損、磨粒磨損和氧化磨損。經(jīng)過(guò)激光沖擊強(qiáng)化處理的TC11鈦合金,在高溫條件下的主要磨損機(jī)制為磨粒磨損和氧化磨損,并且隨著溫度升高氧化磨損程度越嚴(yán)重,氧化磨損引起的材料損失遠(yuǎn)低于剝層磨損。(4)TC11鈦合金激光沖擊后耐磨性提高的主要機(jī)制可歸納為:a、鈦合金激光沖擊強(qiáng)化后,材料的顯微結(jié)構(gòu)和硬度沿深度方向上呈現(xiàn)梯度分布,各層間具有較好的結(jié)合性,表面硬度較高;b、鈦合金經(jīng)過(guò)激光沖擊后表層被壓實(shí),摩擦過(guò)程中形成的機(jī)械混合層比較致密;c、激光沖擊強(qiáng)化后的鈦合金表面殘留較大的殘余壓應(yīng)力,有效減少因裂紋萌生和擴(kuò)展引起的剝層磨損。
[Abstract]:Laser shock peeningine (LSPs) was modified by high pressure and transient plasma shock wave induced by laser shock. In this paper, the wear behavior and wear properties of TC11 titanium alloy under different laser impact parameters and in different environments were studied. SEM was used to improve the wear resistance of the alloy. The morphology, composition and structure of wear mark surface and section were analyzed by EDS, and the main wear patterns of TC11 titanium alloy before and after laser impact were discussed. The mechanism of enhancing wear resistance of TC11 at high temperature by laser shock strengthening was analyzed. It lays a theoretical foundation for the study of friction and wear properties of titanium alloys under high temperature. The main contents and conclusions of this paper are as follows: 1). Laser impact process parameters have great influence on the friction properties of TC11 titanium alloy. With the increase of the number of laser shock layers, the time of the friction coefficient reaching stability is shorter. The friction coefficient of laser impact specimen decreases gradually with the increase of temperature and the fluctuation is small. The friction coefficient of the sample before and after laser shock increases with the increase of load. A gradual increasing trend. 2) the wear resistance of TC11 titanium alloy can be significantly improved by laser impact strengthening technology. The wear resistance of titanium alloy increases gradually with the increase of laser impact layer number. 600 擄C and below. The wear resistance of TC11 titanium alloy increases with the increase of temperature, while the wear resistance of unimpacted titanium alloy increases first with the increase of temperature and then decreases under .25N. The wear rate of titanium alloy increases with the increase of load before and after laser impact. However, after laser impact, the wear rate of titanium alloy is smaller. 3) there are many cracks on the surface of wear mark of unimpacted specimen. The main wear mechanisms were delamination, abrasive wear and oxidation wear. The TC11 titanium alloy was strengthened by laser impact. The main wear mechanisms at high temperature are abrasive wear and oxidation wear, and the degree of oxidation wear becomes more serious with the increase of temperature. The material loss caused by oxidation wear is much lower than that of delamination wear. TC11 titanium alloy after laser impact. The main mechanism of improving wear resistance can be summarized as: 1: a, after laser shock hardening of titanium alloy. The microstructure and hardness of the material show gradient distribution along the depth direction. The surface layer of b-, titanium alloy is compacted after laser impact, and the mechanical mixing layer formed in the process of friction is compact. The large residual compressive stress on the surface of titanium alloy strengthened by laser shock can effectively reduce the delamination and wear caused by crack initiation and propagation.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TG146.23;TG665

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李正陽(yáng);蔡振兵;吳艷萍;朱e，

本文編號(hào)：1390725