本文選題：硬質(zhì)合金 + 硬質(zhì)相　； 參考：《材料導(dǎo)報》2017年08期

【摘要】：采用兩步法燒結(jié)工藝制備了表面富Co-layers硬質(zhì)合金和表面富Ti基硬質(zhì)相層硬質(zhì)合金,對比研究了氮化處理前后硬質(zhì)合金表面微觀形貌、生成相和力學(xué)性能的差異。研究表明:真空條件下燒結(jié)可在試樣表層生成約20μm厚的Co-layers,該層中不含立方碳化物相,微觀結(jié)構(gòu)分析發(fā)現(xiàn)試樣表面呈現(xiàn)山丘形貌且具有金屬亮銀色光澤,可用于修復(fù)試樣表面缺陷,如微觀裂紋、孔洞等,并且改善硬質(zhì)合金表面韌性和提高涂層與基體之間的界面結(jié)合強度。氮化處理可在合金表面原位生成富含細晶粒的TiN相層,層厚約1μm,微觀結(jié)構(gòu)分析發(fā)現(xiàn)該層呈金色或棕色,表面較為平整。通過性能對比分析發(fā)現(xiàn)滲氮雖然導(dǎo)致試樣密度小幅降低,但是可顯著改善晶粒尺寸分布不均和增加表層硬質(zhì)相中的微應(yīng)變,能夠在提高表面硬度的同時依然保持較高韌性,同時可有效改善硬質(zhì)合金的刀具耐磨性和使用壽命。
[Abstract]:The surface cemented carbides rich in Co-layers and Ti-based cemented carbides were prepared by two-step sintering process. The surface morphology, phase formation and mechanical properties of the cemented carbides before and after nitriding were compared and studied. The results show that Co-layers20 渭 m thick can be formed on the surface of the sample by sintering under vacuum condition. There is no cubic carbide phase in the layer. The microstructure analysis shows that the surface of the sample has a mound shape and a bright silver metallic gloss. It can be used to repair surface defects, such as micro-cracks, pores, etc., and to improve the surface toughness of cemented carbides and the interfacial bonding strength between coating and substrate. After nitriding, the TiN layer rich in fine grains was formed on the surface of the alloy. The thickness of the layer was about 1 渭 m. The microstructure of the layer was found to be golden or brown, and the surface was flat. It is found that nitriding can significantly improve the uneven distribution of grain size and increase the micro-strain in the hard phase of the surface layer although nitriding leads to a small decrease in the density of the sample. The nitriding can increase the hardness of the surface and maintain the high toughness at the same time. At the same time, it can effectively improve the wear resistance and service life of cemented carbide tools.
【作者單位】： 嶺南師范學(xué)院機電工程研究所;廣東工業(yè)大學(xué)機電工程學(xué)院;
【基金】：廣東省自然科學(xué)基金(S2013010012107) 廣東省揚帆計劃科研創(chuàng)新團隊項目(411282606110) 嶺南師范學(xué)院科研創(chuàng)新團隊項目;嶺南師范學(xué)院新材料與先進制造協(xié)調(diào)創(chuàng)新中心項目
【分類號】：TG156.82
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本文編號：1928534