本文選題：模具材料　切入點(diǎn)：等離子噴焊　出處：《西華大學(xué)》2017年碩士論文

【摘要】：模具是用來制作成型物品的工具,現(xiàn)已成為制造業(yè)的重要核心部分。其種類繁多,如沖壓模具、塑料模具、壓鑄模具、玻璃模具等,應(yīng)用也十分廣泛。模具在服役過程中會(huì)受到高溫、高壓、交變熱應(yīng)力等影響,特別是模具的成型零件與制品之間產(chǎn)生摩擦磨損,這些因素會(huì)造成模具零件,特別是成型零件的失效或報(bào)廢。如何修復(fù)模具,提高模具耐磨性能,延長模具使用壽命等工作是模具領(lǐng)域的重要研究課題。本文以等離子噴焊技術(shù)為手段,選擇45鋼、H13熱作模具鋼、HT250灰口鑄鐵為基材,選用鎳基合金粉末Ni45A和Ni60B,制備45鋼-Ni45A、45鋼-Ni60B、H13-Ni45A、HT250-Ni45A噴焊試樣。研究等離子噴焊層制備的工藝參數(shù),噴焊層與基材的結(jié)合情況,微觀組織,力學(xué)性能,以及摩擦磨損性能。主要研究?jī)?nèi)容和結(jié)論如下:1.對(duì)等離子噴焊層的微觀組織研究表明:45鋼-Ni45A和45鋼-Ni60B噴焊層的顯微組織主要為胞狀晶和樹枝晶,H13-Ni45A和HT250-Ni45A噴焊層的顯微組織主要為胞狀晶和柱狀晶。經(jīng)EDS分析發(fā)現(xiàn),合金元素在噴焊層與基材之間相互擴(kuò)散,噴焊層與基材形成明顯的結(jié)合區(qū)。經(jīng)SEM分析發(fā)現(xiàn),各噴焊層中均存在白色和灰色相,在45鋼-Ni60B和HT250-Ni45A噴焊層中還存在黑色相。通過XRD分析得出,各噴焊層中均含有富Ni的γ-Ni、FeNi3等基體相和M7C3(Cr7C3、(Cr,Fe)7C3)、M23C6(Cr23C6、(Cr,Fe)23C6)等硬質(zhì)相,其中(Cr,Fe)7C3、(Cr,Fe)23C6分別是以Cr7C3、Cr23C6為基礎(chǔ),溶有Fe原子的碳化物。白色相主要為含Ni、Fe的化合物,灰色相主要為M7C3碳化物,黑色相主要為M23C6碳化物。2.力學(xué)性能研究表明:等離子噴焊層的顯微硬度均明顯高于基材,Ni60B噴焊層的顯微硬度高于Ni45A噴焊層的顯微硬度。細(xì)小的M23C6、M7C3等碳化物能提高抗拉強(qiáng)度和屈服強(qiáng)度。3.對(duì)等離子噴焊層的摩擦磨損性能研究表明:隨摩擦磨損時(shí)長和載荷的增加,45鋼-Ni45A和45鋼-Ni60B噴焊層的摩擦系數(shù)減小,磨損量增加。45鋼-Ni45A噴焊層的摩擦系數(shù)能達(dá)到0.15,45鋼-Ni60B噴焊層的摩擦系數(shù)能達(dá)到0.11,均明顯低于基材45鋼的摩擦系數(shù)(約0.7)。45鋼-Ni60B噴焊層較45鋼-Ni45A噴焊層的耐磨性好。在摩擦磨損前期,45鋼-Ni45A噴焊層磨損面出現(xiàn)少量的粘著顆粒,45鋼-Ni60B噴焊層磨損面為輕微磨損,磨損機(jī)制主要為粘著磨損。隨摩擦?xí)r長和載荷的增加,45鋼-Ni45A噴焊層磨損面出現(xiàn)磨損凹坑,45鋼-Ni60B噴焊層磨損面出現(xiàn)犁溝,甚至有較大的剝落坑,磨損機(jī)制主要為磨粒磨損和疲勞磨損。4.本文研究表明:在45鋼、H13、HT250基材上噴焊Ni45A、Ni60B合金粉末制備噴焊層以修復(fù)模具材料是可行的,噴焊層與基材可以達(dá)到冶金結(jié)合。
[Abstract]:Molds are tools used to make moulding objects and have become an important core part of manufacturing.Its variety, such as stamping die, plastic mold, die-casting mold, glass mold, and so on, is also widely used.The die will be affected by high temperature, high pressure and alternating thermal stress during service, especially the friction and wear between the molded parts and the products. These factors will lead to the invalidation or scrapping of the mould parts, especially the molded parts.How to repair the mould, improve the wear resistance and prolong the service life of the die is an important research topic in the field of mould.Based on plasma spray welding technology, 45 steel H13 hot working die steel / HT250 gray cast iron was selected as base material, and Ni-base alloy powder Ni45A and Ni60B were used to prepare 45 steel -Ni45AH13-Ni45A H13-Ni45A HT250-Ni45A spray welding specimen.The process parameters of plasma spray welding coating, the bonding between the coating and the substrate, the microstructure, the mechanical properties and the friction and wear properties were studied.The main contents and conclusions are as follows: 1.The microstructure of plasma spray welding layer shows that the microstructures of the spray-welding coatings are mainly cellular crystal and dendritic H13-Ni45A and HT250-Ni45A spray welding layer, which are mainly cellular crystal and columnar crystal in the spray-welding layer of% 45 steel -Ni45A and 45 steel -Ni60B. The microstructure of the coating is mainly cellular crystal and dendritic H13-Ni45A layer and HT250-Ni45A spray welding layer is mainly cellular crystal and columnar crystal.By EDS analysis, it was found that the alloy elements diffused between the spray welding layer and the substrate, and the bonding zone between the spray welding layer and the substrate was obvious.It was found by SEM analysis that white and gray phases existed in all spray welding coatings and black phases were also found in 45 steel Ni60B and HT250-Ni45A spray welding coatings.閫氳繃XRD鍒嗘瀽寰楀嚭,鍚勫柗鐒婂眰涓潎鍚湁瀵孨i鐨勎，

本文編號(hào)：1704448