基于球压法的水泥熟料在不同温度下的力学性能分析

ANALYSIS OF MECHANICAL PROPERTIES OF CEMENT CLINKER UNDER DIFFERENT TEMPERATURES BASED ON HERTZIAN INDENTATION METHOD

本文通过高温球压法得到各种脆性和准脆性材料的表面压痕应力与应变之间的关系曲线。通过压痕应力–应变曲线的分析既可比较方便地确定出材料的压痕弹性模量、剪切模量和布氏硬度,又可比较不同温度下水泥熟料的变形性能。在不同温度(25℃1400℃)处理下,球压应力松弛试验载荷松弛,在载荷峰值为100 N时,随着温度的升高,水泥熟料载荷松弛更明显。随着温度从500℃升高到1400℃,载荷松弛非常明显,尤其温度高于1200℃,水泥熟料样品内部的硅酸三钙(Ca3SiO5,简称C3S)分解以及有部分液相的出现引起的应力松弛现象最为明显,在1275℃时熟料基本上已经软化,载荷急速松弛,所以认为1275℃为熟料的脆延转化温度。通过水泥熟料高温球压松弛试验可以确定水泥熟料在二次加热过程中的脆–延转化温度,测定熟料弹性模量和抗压强度急剧变化的温度范围。研究水泥熟料在不同温度下的力学行为和力学特性,探索提高粉磨效率的新途径,实现高温下的低能耗粉碎。

In this paper, the relationship between stress and strain on the surface of brittle or quasi brittle materials is obtained by the high temperature Hertzian indentation method. According to the analysis of the indentation stress strain curve, the indentation modulus, the shear modulus and the hardness of the material can be determined and the deformation properties of the cement clinker are compared. Under the high temperature heat treatment of different temperatures(25℃~1400℃), the stress relaxation of the Hertzian indentation is observed. When the load peak value is 100 N, the load relaxation of the cement clinker is more obvious with the increase of the temperature. With the temperature increasing from 500℃ to 1400℃, the load relaxation is very significant, especially at 1200℃. For the cement clinker samples within the C3S decomposition and the partial liquid phase, the stress relaxation is observed, most obviously at 1275℃, the clinker softened, and the relaxation load is 0N. So 1275℃ is the brittle ductile transition temperature of the clinker. The brittle plastic transition temperature of the cement clinker during the two heating processes can be determined by the high temperature Hertzian indentation relaxation test for the cement clinker. The temperature range for the sharp change of the elastic modulus and the compressive strength of the clinker can be determined. To study the mechanical behavior and the mechanical properties of the cement clinker at different temperatures, new ways to improve the grinding efficiency should be explored.