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A novel method for thermal diffusivity evolution of thin-film materials with pulsed Gaussian beam and infrared video is reported. Compared with common pulse methods performed in specialized labs, the proposed method implements a rapid on-line measurement without producing the off-centre detection error. Through mathematical deduction of the original heat conduction model, it is discovered that the area s, which is encircled by the maximum temperature curve rTMAX(θ), increases linearly over elapsed time. The thermal diffusivity is acquired from the growth rate of the area s. In this study, the off-centre detection error is avoided by performing the distance regularized level set evolution formulation. The area s was extracted from the binary images of temperature variation rate, without inducing errors from determination of the heat source centre. Thermal diffusivities of three materials, 304 stainless steel, titanium, and zirconium have been measured with the established on-line detection system, and the measurement errors are: −2.26%, −1.07%, and 1.61% respectively.

An effective compound thermal diffusivity characterization method is proposed for the layer-structured polymer composites.

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The La2Zr2O7/SrZrO3 composite with a mol ratio of 1:2 named (La0.5Sr0.5)ZrO3.25 (LSZ) was in-situ synthesized by co-precipitation method using ammonia and ammonium oxalate as precipitants. The synthesized LSZ powder showed good phase stability not only from room temperature to 1400°C but also at higher temperature of 1450°C for a long period, as analyzed by thermogravimetry, differential scanning calorimetry and X-ray diffraction, respectively. The bulk LSZ with relative density >95% was prepared by pressureless sintering at 1500°C for 2 h and spark plasma sintering (SPS) at 1300°C for 5 min, respectively. The fracture toughness of the bulk LSZ prepared by both pressureless sintering and SPS were 1.80±0.20 MPa·m1/2 and 1.95±0.09 MPa·m1/2, respectively, which are higher than that of both bulk SrZrO3 and La2Zr2O7. The coefficients of thermal expansion (CTEs) of the bulk LSZ were 8.4-9.5×10-6 K-1 in a temperature range of 200-1200°C, which are higher than that of La2Zr2O7 but lower than that of SrZrO3. The thermal conductivity of the bulk LSZ prepared by pressureless sintering was ~1.1 W·m-1·K-1 at 1000°C, which is lower than that of both bulk SrZrO3 and La2Zr2O7. The LSZ composite is considered as a promising thermal barrier coating material.