(江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013)
摘 要: 以0.8 mm鈦片作為填充材料，采用純氬和氮氬混合等離子氣體對SiCp/Al基復(fù)合材料進(jìn)行等離子弧原位焊接，分析加入的N2對焊縫成形、焊縫組織和性能的影響。結(jié)果表明，隨氮氣體積分?jǐn)?shù)增大，焊縫熔深也相應(yīng)增大：增加氮氣還改善了熔池中的熱循環(huán)狀態(tài)和冶金反應(yīng)，生成TiN、AlN等新的增強(qiáng)相，有效地抑制脆性相的生成，改善了焊接接頭的性能。力學(xué)性能實驗表明，采用Ar+N2作為離子氣進(jìn)行焊接時，焊縫硬度和強(qiáng)度都有提高。當(dāng)N2體積分?jǐn)?shù)約占15%時，拉伸強(qiáng)度達(dá)到最大值233.5 MPa。
關(guān)鍵字: SiCp/Al基復(fù)合材料；原位焊接；Ar+N2；組織
of SiCp/Al MMCs
（School of Material Science and Engineering, Jiangsu University,
Zhenjiang 212013, China）
Abstract: In order to analyze the weldability of SiC particle reinforced aluminum metal matrix composites(SiCp/Al MMCs), Plasma arc in-situ welding of SiCp/Al MMCs was carried out using pure argon and argon-nitrogen mixture as plasma gases with 0.8 mm thick titanium filler-plate as in-situ material. The effect of nitrogen addition into plasma gases on the appearance of weld, microstructure and mechanical properties was investigated. The results show that when the nitrogen volume increases, the weld penetration also correspondingly increases. The thermal cycle state and metallurgy response of the molten poor are also improved by adding nitrogen. A new composite reinforced by TiN, AlN is produced in the weld, effectively suppressing the formation of Al4C3, consequently ensuring the quality of joints. The mechanical testing results show that the microhardness and tensile strengths of joins welded by adding nitrogen are both increased. The highest tensile strength of joints is 233.5 MPa when the nitrogen volume is approximately 15%.
Key words: SiCp/Al MMCs; plasma arc in-situ welding; Ar+N2; microstructure
