(上海交通大學(xué) 金屬基復(fù)合材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，上海 200240)
摘 要: 以Ti-6Al-4V合金和(TiB+La2O3)/Ti-6Al-4V 復(fù)合材料為研究對(duì)象，研究固態(tài)滲碳法對(duì)兩種材料表面顯微組織和硬度的影響規(guī)律。將包覆于石墨粉中的試樣置于密封的石英管中，在1227 K下保溫24 h，成功實(shí)現(xiàn)了兩種材料表面滲碳處理。顯微組織和物相分析結(jié)果表明，固態(tài)滲碳后基體中原位生成了TiC 增強(qiáng)體和Ti-C 固溶體，且擴(kuò)散層中的等軸α-Ti 相的體積分?jǐn)?shù)隨試樣深度增加呈明顯降低趨勢(shì)；硬度測(cè)試結(jié)果表明，兩種材料滲碳表面的顯微硬度與未處理材料相比都明顯提高了約100%，隨試樣深度增加而變化的碳含量在滲碳試樣中形成了約300 μm 的硬化層。同時(shí)，固態(tài)滲碳對(duì)內(nèi)部組織和硬度的影響很小，表明該方法是一種有效強(qiáng)化鈦合金及其復(fù)合材料的表面處理方法。
關(guān)鍵字: 鈦合金；鈦基復(fù)合材料；固態(tài)滲碳；顯微組織；顯微硬度
（State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China）
Abstract:Solid carburization was employed to improve the hardness of Ti-6Al-4V alloy and (TiB+La2O3)/Ti composite. The samples wrapped in graphite powder were placed in sealed quartz tubes, followed by solid carburization at 1227 K for 24 h. Microstructure and phase analysis indicated that TiC reinforcements and Ti-C solid solutions were introduced after solid carburization. Moreover, the volume fraction of equiaxed α-Ti phase in diffusion layer decreased obviously with increasing sample depth. Hardness testing results indicated that both the carburized surfaces performed significant improvement of about 100% in micro-hardness compared with untreated materials. The variation of carbon contents with increasing sample depth resulted in a hardened layer of 300 μm in the carburized samples. Meanwhile, slight influence on the internal microstructure and hardness indicated that solid carburization was an effective method in strengthening the surface of titanium alloy and titanium matrix composite.
Key words: titanium alloy; titanium matrix composite; solid carburization; microstructure; micro-hardness
