难变形材料热静液挤压复合精密塑性成形工艺

目的 研究热静液挤压及其复合塑性变形工艺在高密度钨合金、钨铜合金、钛基复合材料及镁合金薄壁细管等难变形材料方面的制备。方法 通过对高密度钨合金难变形材料进行热静液挤压及旋转锻造等塑性成形，分析了材料在成形过程中的微观组织及性能变化规律和强化机制，制备出大长径比穿甲弹弹芯材料。在此基础上，将该复合塑性变形技术拓展至两相不互溶材料钨铜合金、钛基复合材料及大长径比镁合金毛细管等难变形材料方面的制备。结果 热静液挤压及其复合塑性变形工艺在粉末冶金难变形材料的致密化方面具有显著优势，获得材料不仅致密度高，而且有效实现了控形控性；对于镁合金薄壁细管成形而言，也可以实现组织与性能的有效调配，同时材料的精度较高。结论 热静液挤压及其复合塑性变形工艺在难变形材料的制备与成形方面具有独特的优势与广阔的应用前景。

Hard-deformation Material Fabricated by Hot Hydrostatic Extrusion and Compound Precision Plastic Forming Technologies

The paper aims to study fabrication of tungsten heavy alloy, tungsten copper alloy, titanium matrix composite and thin-wall tube of magnesium alloy and other hard deformation materials. Based on plastic deformation of high density tungsten alloys, such as hot hydrostatic extrusion and rotary forging, change rules and strengthening mechanisms for microstructure and properties of materials in the forming process were analyzed to fabricate materials for bullet core of armour-piercing bullet of large aspect ratio. On this basis, the compound plastic deformation technology was extended to preparation of two phase immiscible materials, such as tungsten copper alloy, titanium matrix composite and thin-wall tube of magnesium alloy with large aspect ratio and other hard deformation materials. Hot hydrostatic extrusion and compound plastic deformation process in densification of powder metallurgy materials had significant advantages, not only materials of high density were obtained, and control of shape and properties was achieved; for the fabrication of thin-wall tube of magnesium alloy, effective allocation of microstructure and properties could also be realized and the material also had high precision. Therefore, hot hydrostatic extrusion and its composite plastic deformation technologies have unique advantages and broad application prospects in the preparation and forming of hard-deformation materials.