Substantial enhancement of mechanical properties for SnSe based composites with potassium titanate whiskers

Abstract

Highly dense p-type polycrystalline SnSe dispersed with x vol% K2Ti6O13 whiskers (x = 0, 1, 3, 5) were fabricated by a high-pressure sintering (HPS) method. The effects of the K2Ti6O13 whiskers additives on the thermoelectric as well as mechanical properties of the composites were characterized in detail. The electrical conductivity, Seebeck coefficient, and thermal conductivity were measured within the temperature range of 300–830 K. It was found that the K2Ti6O13 whiskers were distributed homogeneously throughout the matrix and contacted with the SnSe grains intimately. Mechanical properties, such as Vickers hardness, flexural strength, compressive strength and fracture toughness of the composites were improved significantly. Especially, upon the addition of 5 vol% K2Ti6O13 whiskers, the flexural strength and compressive strength were almost doubled as compared to K2Ti6O13-free samples. Such substantial enhancement of mechanical properties is an important benefit for the commercial application of thermoelectric devices.