本文選題：粉末冶金　切入點(diǎn)：鎳基復(fù)合材料　出處：《天津工業(yè)大學(xué)》2017年碩士論文

【摘要】：鎳基合金憑借其優(yōu)秀的耐腐蝕性和耐熱性,在航空航天、軍事、化工、汽車制造業(yè)等領(lǐng)域都有著廣泛的應(yīng)用,但其本身存在硬度和自潤滑性能較差等特點(diǎn)。本文采用粉末冶金法制備了 Ni-WC復(fù)合材料和Ni-MoS2復(fù)合材料,利用光學(xué)金相顯微鏡、X射線衍射、掃描電鏡、能譜儀、洛氏硬度計(jì)等分析手段研究了 Ni-WC、Ni-MoS2復(fù)合材料的燒結(jié)工藝和增強(qiáng)相WC、MoS2的含量對Ni基復(fù)合材料組織性能的影響;并對Ni基復(fù)合材料進(jìn)行熱處理,研究了固溶處理和時(shí)效處理對Ni基復(fù)合材料組織性能的影響,優(yōu)化熱處理工藝參數(shù)。研究結(jié)果表明:1、采用粉末冶金法技術(shù),在優(yōu)化制備工藝參數(shù)條件下制備出了 Ni/WC鎳基復(fù)合材料和Ni/MoS2鎳基復(fù)合材料,材料致密度較高,增強(qiáng)相顆粒均勻分布在Ni基體中。2、當(dāng)合金中添加WC顆粒后,燒結(jié)時(shí),部分WC溶解在γ-Ni中,另一部分WC顆粒則均勻分布在合金中,冷卻時(shí),γ-Ni中析出大量的第二相,合金硬度隨WC含量的增加而提高。當(dāng)合金中添加MoS2時(shí),隨著MoS2含量的增加,合金中(γ-Ni+NiMo)共晶組織數(shù)量增加,合金中部分Cr溶解在NiMo金屬間化合物中形成Ni(Mo,Cr),導(dǎo)致合金中M7C3碳化物數(shù)量的減少,第二相強(qiáng)化作用減弱,合金硬度較低。3、通過對燒結(jié)后樣品組織分析可知:Ni60合金中主要由γ-Ni樹枝晶、M7C3(M為Cr、Fe和Ni)碳化物、Ni3B顆粒和共晶組織(γ-Ni+Ni3B)組成;Ni-WC合金中主要由γ-Ni、碳化物M7C3、WC和共晶組織(γ-Ni+Ni3B)組成;Ni-MoS2合金中主要由γ-Ni樹枝晶、M7C3碳化物、Ni3B顆粒、共晶組織1(γ-Ni+Ni3B)和共晶組織2(γ-Ni+NiMo)組成。4、Ni60合金經(jīng)固溶處理后,合金主要由γ-Ni過飽和固溶體和碳化物M7C3組成;Ni60+10%WC合金經(jīng)固溶處理后,合金主要由γ-Ni過飽和固溶體、碳化物M7C3和WC組成。固溶處理后的合金,在300℃～500℃之間進(jìn)行時(shí)效處理時(shí),合金中析出物數(shù)量不斷增加,第二相強(qiáng)化效果顯著,合金硬度上升,當(dāng)時(shí)效處理溫度為500℃左右時(shí),合金的硬度達(dá)到最大值,繼續(xù)提高時(shí)效溫度,第二相不斷聚集長大,彌散程度降低,第二相強(qiáng)化效果減弱,因此當(dāng)合金時(shí)效處理溫度在500℃～700℃時(shí),合金的硬度逐漸下降。
[Abstract]:Nickel-based alloys have been widely used in aerospace, military, chemical, automobile manufacturing and other fields because of their excellent corrosion resistance and heat resistance. In this paper, Ni-WC and Ni-MoS2 composites were prepared by powder metallurgy method. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy spectrometer (EDS) were used to prepare the composites. By means of Rockwell hardness meter, the sintering process of Ni-WCU Ni-MoS2 composite and the effect of the content of reinforced phase WCCnMoS2 on the microstructure and properties of Ni matrix composite were studied, and the heat treatment of Ni matrix composite was carried out. The effects of solution treatment and aging treatment on the microstructure and properties of Ni matrix composites were studied, and the heat treatment parameters were optimized. Ni/WC nickel matrix composites and Ni/MoS2 nickel matrix composites were prepared under the condition of optimized preparation process parameters. The densities of the composites were high, and the reinforcement particles distributed uniformly in Ni matrix. When WC particles were added to the alloy, the composites were sintered. Some WC dissolved in 緯 -Ni, the other WC particles distributed uniformly in the alloy. When cooling, a large number of second phases were precipitated in 緯 -Ni. The hardness of the alloy increased with the increase of WC content. When MoS2 was added to the alloy, the content of MoS2 increased. The amount of (緯 -Ni NiMo) eutectic structure in the alloy increases, and some Cr in the alloy dissolves in the NiMo intermetallic compound to form NiHMo-Cr-O, which results in the decrease of the amount of M7C3 carbides in the alloy and the weakening of the second phase strengthening effect. The hardness of the alloy is relatively low. The microstructure analysis shows that the Ni-WC alloy is mainly composed of 緯 -Ni dendrite M 7C 3N M carbide Ni _ 3B particles and eutectic microstructure (緯 -Ni Ni _ 3B), mainly composed of 緯 -Ni, M _ 7C _ 3U _ WC and eutectic microstructure (緯 -Ni _ 3B), which are mainly composed of 緯 -Ni dendrite (M _ 7C _ 3N _ 3C _ 3M) particles and eutectic microstructure (緯 -Ni). Ni3B) is mainly composed of 緯 -Ni dendritic M _ 7C _ 3 carbides and Ni _ 3B particles in Ni-MoS _ 2 alloy. The eutectic structure 1 (緯 -Ni Ni 3B) and eutectic structure 2 (緯 -Ni Ni Ni Mo). After solution treatment, the alloy mainly consists of 緯 -Ni supersaturated solid solution and carbides M7C3. The alloy is mainly composed of 緯 -Ni supersaturated solid solution, and the alloy is mainly composed of 緯 -Ni supersaturated solid solution. The composition of carbides M7C3 and WC. The amount of precipitates in the alloy after aging treatment at 300 鈩，

本文編號：1674566