復(fù)合涂層結(jié)構(gòu)的影響
(1． 華中科技大學(xué) 模具技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，武漢 430074;
2． 武漢理工大學(xué) 材料科學(xué)與工程學(xué)院，武漢 430070;
3． 武漢理工大學(xué) 材料復(fù)合新技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，
武漢 430070)
摘 要: 將自蔓延高溫合成（SHS）技術(shù)與鑄造工藝結(jié)合起來， 制備了鑄造鋼基表面TiC-Fe梯度復(fù)合材料, 研究了鋼液的澆注溫度、 Ti-C-Fe預(yù)制塊的組成及其相對(duì)密實(shí)度等工藝參數(shù)對(duì)梯度復(fù)合涂層結(jié)構(gòu)的影響。 結(jié)果表明： 在保證預(yù)制塊能被澆注的鋼液直接點(diǎn)燃的條件下，適當(dāng)提高鋼液的澆注溫度、 降低預(yù)制塊的密實(shí)度均有利于梯度復(fù)合涂層的形成； 而且在預(yù)制塊中摻加適量的低熔點(diǎn)金屬稀釋劑不僅可降低合成TiC顆粒的尺寸， 而且也有利于梯度復(fù)合涂層的形成。 梯度復(fù)合涂層的形成與鋼液向預(yù)制塊中的滲透、 預(yù)制塊中Fe和低熔點(diǎn)稀釋劑的熔化以及合成的TiC顆粒向鋼液中的擴(kuò)散等作用有關(guān)。
關(guān)鍵字: 鑄造； 自蔓延高溫合成； TiC-Fe涂層；梯度復(fù)合； 工藝參數(shù)
FU Zheng-yi3, WEI Bo-kang1
（1. State Key Lab of Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China;
2. School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China;
3. State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology,Wuhan 430070, China）
Abstract:A TiC-Fe cermet graded composite coating on a cast steel substrate was successfully fabricated by an SHS casting route. The effects of technological parameters, such as pouring temperature of liquid steel, composition of Ti-C-Fe preform and its relative green density, on the microstructure of the coating were emphatically studied. The results show that, under the condition of ensuring the preform to be ignited, properly increasing the pouring temperature of liquid steel and decreasing the green density of the preform are favorable to the formation of the graded composite coating. Furthermore, adding a kind of metal diluents with lower melting point into the preform not only can decrease the size of the synthesized TiC particles, but also is more advantageous for the formation of the graded composite coating. It is considered by analysis that the formation of the graded composite coating is related to the combined effects of the infiltration of the melt into the preform, the fusion of Fe powders and the diluents in the preform, and the converse diffusion of the synthesized TiC particles into the poured melt.
Key words: SHS; TiC-Fe cermet coating; graded composite; technological parameter
