镁合金低压消失模铸造典型缺陷试验研究

  本文关键词：镁合金低压消失模铸造典型缺陷试验研究，由笔耕文化传播整理发布。

华中科技大学硕士学位论文

镁合金低压消失模铸造典型缺陷试验研究

姓名：张大付申请学位级别：硕士专业：材料加工工程指导教师：樊自田

20050430

摘　　要　

镁合金因密度小

成型困难的缺点

低压

消失模铸造新技术

建立了低压消失模铸造过程中金

属液充型的物理和数学模型

用电极触点法记录了镁合金低压消失模

铸造的充型过程

粘砂等典型缺陷，　分析了这些缺陷的形貌特征

提出了减少和消除缺陷的工艺措施

低压消失模铸造新工艺的充型能力大大高于重力消失模铸造

低压消失模铸造能获得轮廓清晰的镁合金薄壁复杂铸件薄壁的镁

在可控的压力及气氛下充型和凝固涂层性能

目的．　　

关键字

浇注系统等多方面因素

气孔等缺陷之

铝

电子工业中的应用迅速增长

Abstract

In the last 10 years, there is a rapid growth of application of magnesium (Mg) alloys in the auto and electronic industries because of its low density and high strength-to-weight ratio, and the lost foam casting (LFC) process is a precision forming technology capable of casting complicated parts with low manufacturing costs. In order to overcome the shortcomings of melt Mg alloy quick oxidation and mould filling difficulty, the Huazhong University of Science and Technology developed a new Low Pressure- Lost Foam Casting (LP-LFC) process for producing Mg alloy castings with thin-wall and complex geometries by combining benefits of LFC with the superiority of low pressure casting (LPC).

This paper analyzes the principle of the LP-LFC process

the casting defects

including short runs, cold laps, trapped gas

birth causes and influence factors of above defects are

discussed in the article

and the new process can largely reduce

or overcome the defects of short runs and cold laps encountered in LFC. The complex thin-walled Mg alloy (or Al alloy) castings can be produced perfectly by LP-LFC, so the new process is very suitable for casting Mg alloy (or Al alloy) parts with high precision and complex thin-walled.

In LP-LFC process, the mould filling and metal freezing are carried out under the controllable pressure and gas environment. The filling course and the defects of short runs and trapped gas are mainly depended on the pressure and flux of filling gas, foam pattern

property, pouring temperature, coating performance, gating system

１　　绪论　

1.1

课题来源

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轻的镁合金材料和消失模铸造成型技术的结合正好满足了这两个方面的设计原则

轻的镁合金

优化结构

比强度

抗辐射能力和减震性强

精确成形

符合21

世纪铸造的发展方向

而且镁资源丰富

消失模技术的最大特点是铸件设计非常灵活

减少加工

从产品的结构轻量化复杂

特别是汽车

术的结合顺应了时代发展要求

消失模铸造工艺的特点非常适合镁合金液态成型华中科技大学

提出了把镁合金

成一种非常适用于优质压镁合金消失模精密铸造技术

镁合金消失模铸件缺陷真空低压消失模铸造

形

即可控气压下真空低

因此镁合金材料和消失模铸造技

镁及其合金有如下优势

[8]

1

2

强的减震性

6

高纯度镁具有更高的抗腐蚀性

塑料

１

耐老化３

  本文关键词：镁合金低压消失模铸造典型缺陷试验研究，由笔耕文化传播整理发布。