树脂砂高温强韧性的测试技术

提出利用断裂力学理论评价树脂砂的强韧性,引入高温当量韧度的概念.利用自行研制的树脂砂高温性能试验仪研究了不同树脂砂的高温当量韧度及其影响因素.

Measurement of the Strengthened Toughness of Resin Sands at Elevated Temperatures

Based on fracture mechanics,the concept of thermal equivalent toughness is employed to evaluate the strengthened toughness of resin sands at elevated temperatures. The principle and function of a self-made apparatus for testing the properties of resin sands at elevated temperatures and a method of measuring the thermal equivalent toughness are described. With a structure for heating the flat bar sample on one side, loading on four fulcrums and measuring the bending strength and deformation separately, the apparatus proposed is capable of better simulating the operating condition of resin-sand molds or cores. The equivalent toughness of furan-resin sands and synthetic fatty-acid sands and the influences of different factors on the toughness have been studied. It has been found that the higher the thermal e-quivalent toughness is,the better the thermal strengthened toughness of resin sands and the stronger the fracture resisting ability will be. Production results show that the tendencies of thermal cracking and deformation of resin sands can be evaluated more accurately by the thermal equivalent toughness.