微波和传统氢气烧结对93W-Ni-Fe正挤压棒坯结构和力学性能的影响

Influence of microwave and conventional hydrogen sintering on microstructure and mechanical properties of 93W-Ni-Fe extruded bars

分别研究93W-Ni-Fe d15 mm挤压棒坯在1 550℃、30 min微波烧结和1 550℃、120 min传统氢气烧结后烧结态的结构及力学性能,并对两种烧结样品芯部的物相及主要元素含量、相对密度、抗拉强度、硬度和伸长率进行测量和分析。结果表明:微波烧结样品中钨的平均晶粒尺寸比传统氢气烧结的小,粘结相中的钨含量比传统烧结的高;断口中部分钨晶粒与粘结相之间存在微裂纹;微波烧结样品硬度为33.8HRC,略高于传统氢气烧结的硬度,其相对密度、抗拉强度和伸长率与传统氢气烧结的接近;对于大尺寸钨合金样品的微波烧结,需要进一步优化微波烧结工艺才能获得比传统氢气烧结更优的结构和力学性能。

The microstructure and mechanical properties of 93W-Ni-Fe powder extruded bars with a diameter of 15 mm sintered via microwave（1 550 ℃,30 min） and conventional hydrogen（1550 ℃,120 min） were investigated, respectively.The phases and quantitative analysis of the main elements in the core portion of samples were measured. The relative density,tensile strength,hardness and elongation of the samples were investigated,respectively.The results show that the average grain size of the alloys sintered via microwave sintering is finer and the tungsten content of the alloys is higher than that via conventional hydrogen sintering.Cracks between part of the tungsten grains and the matrix phase are observed on the fracture of the alloy sintered via microwave sintering.The hardness of the alloys sintered via microwave sintering is 33.8HRC,which is a little higher than that via the conventional hydrogen sintering.The relative density,tensile strength and elongation of the alloys sintered via microwave sintering are fairly close to that via the conventional hydrogen sintering.For the tungsten heavy alloys samples with large size,in order to get the better microstructure and mechanical properties than that via the conventional hydrogen sintering,further optimization of the microwave sintering process is required.