冷压烧结Cu-Fe基金刚石超薄切锯胎体的组织和性能

路阳¹,董洪峰²,李文生¹

(1. 兰州理工大学 甘肃省有色金属新材料国家重点实验室,兰州 730050; 2.陕西理工学院 材料科学与工程学院,汉中 723003)



摘要:

为了研究冷压坯致密化机理及加载速率对烧结胎体组织和力学性能影响,采用单轴模压+热压烧结法,以Cu-Fe基元素混合粉末为原材料,在不同的冷压加载速率条件下制备Cu-Fe基金刚石复合材料超薄切锯胎体；用显微硬度仪、OM、SEM、XRD和万能力学试验机等表征冷压坯显微硬度、组织、烧结胎体组织和力学性能.结果表明:当加载速率较慢时,易变形的Cu、Ni粉在低压下发生加工硬化,抑制后续的塑性变形,阻碍压坯致密化；当加载速率过快时,压坯粉末的塑性变形不充分,造成脱模弹性后效,压坯密度下降；烧结Cu-Fe基胎体以Fe-Cr、(Fe, Ni)、Ni-Cr-Fe、Fe、Cr和(Cu,Sn)为主相；当加载速率为0.1 mm/min时烧结胎体的拉伸强度最大,拉伸断口形貌主要包括塑坑断口、解理断口和沿颗粒脆性断口.

关键词:  单轴模压法  热压烧结  冷压烧结  金刚石复合材料超薄切锯  Cu-Fe基胎体  组织  拉伸强度

DOI：10.11951/j.issn.1005-0299.20140404

分类号:TF124

基金项目:国家自然科学基金资助项目(51165021).



Microstructure and properties of Cu-Fe-based diamond composite ultra thin sawing matrixes during cold pressing sintering

LU Yang¹, DONG Hongfeng², LI Wensheng¹

(1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China;2. School of Materials Science and Engineering, Shanxi University of Technology, Hanzhong 723003, China)

Abstract:

To study the mechanism of cold compaction densification and the effect of loading rate on microstructure and mechanical properties, a Cu-Fe-based diamond composite ultra thin sawing matrix was prepared by uniaxial die pressing and hot pressing technology at different loading rate. The raw material was Cu-Fe-based single element mixed powder; the microhardness and microstructure of green, microstructure and mechanical properties of hot pressed matrixes were investigated by microhardness tester, OM, SEM, XRD, universal mechanical tester, and so on. The densification mechanism of green samples and the effects of load rate on the microstructure and mechanical properties of hot pressed matrixes were also studied. The results show that the work hardening of Cu and Ni powders with good deformability occurs at low pressure when the load rate is lower, which causes deformation succession restrained and green densification inhibited. The deformation of powders is insufficient when the loading rate is excessive higher, which causes more elastic after effect and green density decreased. The main phases of matrixes sintered are Fe-Cr、(Fe, Ni)、Ni-Cr-Fe、Fe、Cr and (Cu,Sn), the tensile strength is the highest at the loading rate of 0.1 mm/min, and there are dimple, cleavage and brittle fracture along with particles.

Key words:  uniaxial die pressing  hot pressing  cold pressing sintering  diamond composite ultra thin sawing  Cu-Fe-based matrix  microstructure  tensile strength