文章信息/Info

Title:

The Effect of Matrix Aluminum Alloy Composition on Microstructure and Mechanical Properties of B4C/Al Composites by Pressureless Infiltration

文章編號:

1674-3962(2020)02-0156-07

作者:

曹雷剛1; 王曉荷1; 崔巖1; 張龍龍2; 楊越1; 劉園1

（1. 北方工業(yè)大學(xué)機械材料與工程學(xué)院，北京 100144）（2. 大連理工大學(xué)機械工程學(xué)院，遼寧 大連 116024）

Author(s):

CAO Leigang1;  WANG Xiaohe1;  CUI Yan1;  ZHANG Longlong2;  YANG Yue1;  LIU Yuan1

（1.Department of Materials Science and Engineering, North China University of Technology, Beijing 100144, China）（2. School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China）

關(guān)鍵詞:

碳化硼; 復(fù)合材料; 無壓浸滲; 界面反應(yīng); 力學(xué)性能

Keywords:

boron carbide;  composite;  pressureless infiltration;  interfacial reaction;  mechanical property

分類號:

TB333.1+2

DOI:

10.7502/j.issn.1674-3962.201809018

文獻標志碼:

A

摘要:

分別選用2024、5056、6061和7075鋁合金，采用顆粒級配相同的碳化硼預(yù)制體（20% 2 μm和80% 38 μm）為增強體，采用無壓浸滲法制備4種高體份B4C/Al復(fù)合材料（分別對應(yīng)標記為2M、5M、6M和7M），研究基體合金成分對復(fù)合材料的物相組成、微觀組織和力學(xué)性能的影響。結(jié)果表明，4種復(fù)合材料均含有A1、B4C、Al3BC、AlB2和富Fe-Mn相，除此之外，2M、5M和7M復(fù)合材料還含有AlB10。4種復(fù)合材料小顆粒碳化硼聚集區(qū)均發(fā)生了劇烈的界面反應(yīng)，生成Al3BC和AlB2。AlB10主要分布于2M、5M和7M復(fù)合材料的大顆粒碳化硼周圍，并與大顆粒碳化硼連成一體。4種復(fù)合材料的洛氏硬度從大到小順序為2M（45.7）、7M（43.1）、5M（41.8）和6M（40.02）。2M、5M和7M復(fù)合材料內(nèi)部發(fā)現(xiàn)有孔洞存在，導(dǎo)致復(fù)合材料彎曲強度和應(yīng)力均較低。這種效應(yīng)在7M復(fù)合材料中最為明顯，其彎曲強度僅為296 MPa。6M復(fù)合材料彎曲強度和應(yīng)變最高，分別為425 MPa和0.183%，這主要是因為在6M復(fù)合材料中，不含AlB10相且殘余鋁合金相對含量較高。

Abstract:

Four kinds of high volume fraction B4C/Al composites were prepared by pressureless infiltration using four different aluminum alloys (2024Al, 5056Al, 6061Al and 7075Al) and B4C preform with the same particle�瞫ize distributions ( 20% 2 μm and 80% 38 μm ), which were named as 2M, 5M, 6M, and 7M, respectively. The effect of matrix alloy composition on the phase composition, microstructure and mechanical properties of the composites was investigated. The results show that all of the composites contain A1, B4C, Al3BC, AlB2, and Fe-Mn-rich phases. Besides, 2M, 5M, and 7M composites also contain the additional phase, AlB10. For all of the composites, the severe interfacial reaction occurred in the aggregation areas of the small B4C particle, with the formation of Al3BC and AlB2. AlB10 is mainly distributed around large B4C particles in 2M, 5M and 7M composites and is integrated with large B4C particles. The Rockwell hardness of the four composites decreased in the sequence 2M (45.7), 7M (43.1), 5M (41.8) and 6M (40.02). The micropores are observed in the 2M, 5M, and 7M composites, resulting in the decrease of the flexural strength and fracture strain of the corresponding composites. Accordingly, 7M composite possesses the lowest flexural strength, being about 296 MPa. Conversely, the flexural strength and fracture strain of the 6M composite are the highest, being about 425 MPa and 0.183%, respectively. This could be mainly attributed to the absence of AlB10 phase and the highest fraction of the residual aluminum matrix in the 6M composite.