Ni-P-ZrO2化学复合镀层对TC4钛合金抗氧化性能和阻燃性能的影响

在TC4钛合金微弧氧化膜表面制备Ni-P-ZrO2化学复合镀层,研究其在600和700℃空气中的抗高温氧化性能,利用脉冲激光烧蚀处理研究其阻燃性能。结果表明,Ni-P-ZrO2化学复合镀层在600和700℃空气中的氧化动力学曲线呈抛物线形状,氧化膜薄且致密,主要以NiO为主,镀层中非晶的NiP相转变成晶态的Ni2P相,具有良好的抗氧化性能。激光烧蚀处理时,Ni-P-ZrO2镀层烧蚀体积、面积分别是TC4烧蚀的1/3和1/2。镀层激光烧蚀处理后,在烧蚀孔洞内部出现柱状晶粒,ZrO2粒子在镀层表面发生团聚,Ni-P-ZrO2化学复合镀层能有效地提高钛合金的阻燃性能。

Effects of Electroless Ni-P-ZrO2 Composite Plating on High Temperature Oxidation Resistance and Flame Retardant Property of TC4 Titanium Alloys

The electroless Ni-P-ZrO2 composite plating was prepared on the micro-arc oxidation processed TC4 alloy. The oxidation resistance of the TC4 alloy and the electroless Ni-P-ZrO2 composite plating were investigated at 600 oC and 700 oC in air, and their flame retardant property was examined by the pulsed laser ablation. The results indicate that the oxidation kinetic curves of electroless Ni-P-ZrO2 composite plating oxidized at 600 oC and 700 oC are parabolic. The oxides scale is thin and compact. The oxides film is mainly composed of NiO and the amorphous NiP phase is transformed into crystalline Ni2P phase, showing excellent oxidation resistance. The ablation volume and area of the electroless Ni-P-ZrO2 composite plating are about 1/3 and 1/2 of those of TC4 alloy, respectively. After pulsed laser ablation, the columnar grains occur in the holes and the ZrO2 particles are reunited on the surface of the plating. This indicates that electroless Ni-P-ZrO2 composite plating can significantly enhance the flame retardant property of the TC4 alloy