Densification of thermal sprayed coatings with spark plasma sintering (SPS)

摘要

Spark plasma sintering of flame sprayed ZrO_2-25MgO have been investigated. The results of which have presented in this paper. The combination of heating and loading have improved the metallurgical and physical properties of coatings compared than as-sprayed coating. The results obtained in the present work can be summarized as follows : 1. The ZrO_2-25MgO coating after SPS exhibited the better interlamellar contact and reduced the porosity. The coating shows the low percentage of porosity (3.5%) compared than the as-sprayed coating (22%). 2. Bond strength and microhardness of coating after SPS is increased by three times compared than as-sprayed coating. The maximum bond strength and the average of microhardness of coatings were 16 MPa and 1200 HV, respectively. 3. XRD analysis indicates that the phase of ZrO_2-25MgO coating was influenced the physical properties of coating. The transformation to mono-clinic-phase induced some cracks and pores which was lowering the bond strength of coating after SPS at 950°C. 10kN.