A review on lightweight materials for defence applications:Present and future developments

The defence sector is now at an advanced level,catering to the global scenario,and countries also invest heavily in research and development.Countries around the world have spent a lot of money on research and development over the years in order to stay ahead of their competitors.Lightweight materials are critical in defence applications because they allow components to be lighter without sacrificing strength.This review provides an overview of the research related to defence applications.The book provides comprehensive details on current trends in the application of lightweight materials in defence.This review also includes historical and current perspectives on defence technologies.It discusses uses of lightweight materials such as metal matrix composites,polymer composites,ceramic matrix composites,fiber composites in defence sectors Finally,the review paper also emphasizes future military applications of lightweight materials.

A strategy for lightweight designing of a railway vehicle car body including composite material and dynamic structural optimization

Rolling stock manufacturers are finding structural solutions to reduce power required by the vehicles,and the lightweight design of the car body represents a possible solution.Optimization processes and innovative materials can be combined in order to achieve this goal.In this framework,we propose the redesign and optimization process of the car body roof for a light rail vehicle,introducing a sandwich structure.Bonded joint was used as a fastening system.The project was carried out on a single car of a modern tram platform.This preliminary numerical work was developed in two main steps:redesign of the car body structure and optimization of the innovated system.Objective of the process was the mass reduction of the whole metallic structure,while the constraint condition was imposed on the first frequency of vibration of the system.The effect of introducing a sandwich panel within the roof assembly was evaluated,focusing on the mechanical and dynamic performances of the whole car body.A mass saving of 63%on the optimized components was achieved,corresponding to a 7.6%if compared to the complete car body shell.In addition,a positive increasing of 17.7%on the first frequency of vibration was observed.Encouraging results have been achieved in terms of weight reduction and mechanical behaviour of the innovated car body.

Energy-absorbing porous materials:Bioinspired architecture and fabrication

Energy-absorbing materials are widely used in transportations,sports,and the military applications.Particularly,porous materials,including natural and artificial materials,have attracted tremendous attentions due to their light weight and excellent energy absorption capability.This review summarizes the recent progresses in the natural and artificial energy-absorbing porous materials.First,we review the typical natural porous materials including cuttlebone,bighorn sheep horn,pomelo peel,and sunflower stem pith.The architectures,energy absorption abilities,and mechanisms of these typical natural materials and their bioinspired materials are summarized.Then,we provide a review on the fabrication methods of artificial energy-absorbing porous materials,such as conventional foaming and three-dimensional(3D)printing.Finally,we address the challenges and prospects for the future development of energy-absorbing porous materials.More importantly,our review provides a direct guidance for the design and fabrication of energy-absorbing porous materials required for various engineering applications.

Dynamic mechanical characteristics and application of constant resistance energy-absorbing supporting material

In deep underground engineering,rock burst and other dynamic disasters are prone to occur due to stress concentration and energy accumulation in surrounding rock.The control of dynamic disasters requires bolts and cables with high strength,high elongation,and high energy-absorbing capacity.Therefore,a constant resistance energy-absorbing(CREA)material is developed.In this study,the dynamic characteristics of the new material are obtained via the drop hammer tests and the Split Hopkinson Pressure Bar(SHPB)tests of the new material and two common bolt(CB)materials widely used in the field.The test results of drop hammer test and SHPB test show that the percentage elongation of CREA material is more than 2.64 and 3.22 times those of the CB material,and the total impact energy acting on CREA material is more than 18.50 and 21.84 times,respectively,indicating that the new material has high elongation and high energy-absorbing capacity.Subsequently,the CREA bolts and cables using the new material are developed,which are applied in roadways with high stress and strong dynamic disturbance.The field monitoring results show that CREA bolts and cables can effectively control the surrounding rock deformation and ensure engineering safety.

Effect of Pyrophyllite Addition on Properties of Lightweight Insulation Refractory Materials

To solve the problem of over-high density of lightweight insulation refractory bricks prepared with fly ash, new lightweight insulation refractory materials with density 〈 0. 89 g · cm^-3 were .synthesized using pyrophyl-lite, .fly ash, and Suzhou clay as the main starting materials and saw dast as the pore forming substance, and controlling the addition of the pyrophyllite （20%, 30% , and 40% by mass ） and the treating temperature （1 250, 1 300, 1 350, and 1 400 ℃ ）. The synthesized materials were characterized by the XRD, SEM and the thermal conductivity measuring in.strument. The results show at pyrophyllite addition of 30% and treat temperature of l 400 ℃ , the material can achieve linear shrinkage of 6. 6%, apparent porosity of 57%, bulk density of 0. 75 g · cm^-3, compressive strength of 2.7 MPa, and thermal conductivity at 350 ℃ of 0. 152 -0. 216 W·（ m·K）^-1.This indicates that the pyrophyllite decomposition at high temperatures forms mullite and amorphous quartz introducing volume expansion, which counteracts some shrinkage at high temperatures. So it is feasible to use pyrophyllite, fly ash waste and clay to prepare lightweight insulation refractory materials.

Research on application of plastic materials in cars

This paper gives analysis of application status and prospect of plastic materials from the aspects of applied material amount comparison,development of new materials & new technologies,lightweight,design conception of new components,recyclability,simplification and diversity of materials,standardization of material specification and presents corresponding conclusions and suggestions.

Preparation of Periclase-forsterite Lightweight Heat-insulating Refractories by Molten Salt Method

Low grade magnesite is one of the main research directions in the future as the raw material for the preparation of magnesia based insulating refractories.Periclase-forsterite(MgO-Mg_(2)SiO_(4)) lightweight insulating refractories were prepared by the molten salt method with high silica magnesite and tertiary talc ore as raw materials by pretreating them to get light burnt magnesia and talc,and NaCl molten salt as the reaction medium.The effects of the NaCl addition,the sintering temperature,the holding time and the raw material ratio on the sample preparation were studied.The results show that when the NaCl addition is 20% of the mass of light burnt magnesia and talc mixture,the sintering temperature is 1 200 ℃,the holding time is 6 h,and m(light burnt magnesia):m(talc)=5:5,the sample has the optimal comprehensive properties:the bulk density of 1.46 g·cm^(-3) and the apparent porosity of 55.0%.In addition,it is found that self-decomposition of talc and the formation of forsterite can form pores inside the sample.

轻量化高速列车制动盘材料-结构研究进展

400 km/h高速列车紧急制动的强热负荷,导致制动盘温升高、温度分布梯度大和热衰减强,已超出钢质制动盘能载极限,开发耐高温强耐磨的制动盘材料,同时提升制动盘通风散热能力成为制动技术发展瓶颈。综述高速制动盘材料从高强度铸钢和锻钢、轻量化铝基复合材料至耐高温耐磨碳陶复合材料和表面改性技术发展历程,随着碳陶复合材料的台架试验和表面改性技术的摩擦磨损试验研究的深化,表面改性轻质复合材料是制动盘材料未来发展方向。概述通风制动盘内部散热层散热筋结构形貌优化、摩擦层表面耐磨性能改善的发展现状,内部散热筋由直通道设计逐渐演化为弯曲、支柱以及分形通道,镂空结构能更好地加速空气流动提高散热;表面摩擦层引入打孔或划线,更易于摩擦粉尘的抛离从而稳定摩擦因数,保持制动效果;但复杂通风导流结构和打孔划线增加了制备工艺的难度,提出高速制动盘结构构型设计需要综合材料热力学性能、制备工艺及耐热耐磨需求,形成材料-结构-功能—体化设计理念,为实现更高速的制动盘优化设计提供参考。

新能源汽车轻量化设计与材料创新:提高能源利用效率和续航里程的方法研究

随着环境保护意识的增强和能源危机的加剧,新能源汽车作为替代传统燃油车辆的重要选择备受关注。新能源汽车在续航里程和能源利用效率方面仍存在挑战。轻量化设计和材料创新成为提升新能源汽车性能的关键。本研究旨在探讨如何通过轻量化设计和材料创新,提高新能源汽车的能源利用效率和续航里程,为推动新能源汽车行业的可持续发展提供有效方法和理论支持。文章旨在探讨新能源汽车轻量化设计的意义、关键技术、挑战与解决方案,以及未来发展方向。

粉煤灰-矿渣基免烧人造轻集料的制备及性能研究

为减轻对自然资源的开采,合理有效地利用粉煤灰(FA),本工作以FA和磨细粒化高炉矿渣(GGBFS)为原料制备了碱激发免烧人造轻集料(CAALA),研究了原材料配合比对CAALA的造粒效率、物理性能以及抗冻融性能的影响,并分析了CAALA的碱溶出。结果表明,FA掺量对CAALA的性能具有显著影响,当FA掺量增加,水化产物中C-A-S-H凝胶量减少,CAALA中有害孔(>200 nm)的占比增加;结合造粒效率与筒压强度,FA与GGBFS最佳质量比为1∶1,此时CAALA的造粒效率为92.01%、堆积密度为1072 kg/m^(3)、1 h吸水率为10.8%,筒压强度为14.65 MPa,24 h溶出液的pH为11.87,经过15次冻融循环后的质量损失率为3.34%,可供C30等级以下的非结构混凝土使用。

防弹头盔选材及结构设计对其防护性能的影响

防弹头盔是单兵作战时不可缺少的重要防护装备。防弹头盔的防护性能主要受其选材和结构设计的影响。通过总结国内外防弹头盔的选材,结构设计及对应防护机理的相关研究进展,对目前防弹头盔广泛使用的纤维增强复合材料的纤维类型和织物组织结构进行了探讨;概述了现有防弹头盔的盔体、紧固和减震等各方面的结构设计,并通过总结测试实验和仿真模拟,多角度分析了其防护性能。考虑到复杂多变的战场环境,未来的防弹头盔的材料研发和结构设计要向兼具高防护性能和轻量化发展,还需集成更多的智能化装备。

复合材料热压-注塑一体成型技术综述

纤维增强的树脂基复合材料具有比强度较高、比模量较高、质量较轻等特点,在汽车、航天航空、建筑、新能源开发领域中得到广泛应用。在保证零部件使用性能及行驶安全性的前提下,开发汽车轻量化技术,实现整车减重是整个工业领域共同追求的目标。结合连续纤维增强的树脂基热压件与注塑件组合成型,提出了一种热压-注塑一体的成型新工艺。综述了纤维增强的热塑性树脂基复合材料热压-注塑一体成型技术的研究进展,简要介绍了一体成型工艺不同于传统两步成型法的优势与应用,详细阐述了热压-注塑一体成型关键技术的研究现状,最后,对热压-注塑一体成型技术的发展前景进行展望。

航空航天先进结构材料技术现状及发展趋势

先进材料技术是航空航天高新装备的发展先导,是支撑现代工业的关键基础技术,渗透到国防建设、国民经济和社会生活等方方面面,已成为世界各国争相发展的技术高地和国防重点。本文梳理分析航空航天先进结构材料近年来的技术现状及发展趋势,在高性能高分子材料及其复合材料、高温与特种金属结构材料、轻质高强金属及其复合材料、先进结构陶瓷及其复合材料四方面进行重点阐释,明确我国航空航天结构材料的研发与生产仍面临着跟踪研仿多、自主创新少、技术封锁严重、技术瓶颈亟待突破等困境。同时,本文对航空航天结构材料未来研究和发展提出展望,点明建立“产-学-研-用”完整技术体系的重要性。

电动汽车电池箱轻量化设计

对电池箱进行轻量化设计时,为选择合适的轻质材料,使其与电池箱不同位置板件进行匹配以充分发挥材料性能,采用基于CRITIC权重的TOPSIS法和正交试验的方法。建立了电池箱常用金属材料各项性能的决策矩阵,使用基于CRITIC权重的TOPSIS法进行标准化处理,消除不同组数据的量纲差异,确定各组数据的客观权重,计算各方案的相对贴合度,从中选出备选材料;使用正交试验设计和极差分析将备选材料与电池箱不同板件进行匹配,得到多材料电池箱,对多材料电池箱进行尺寸优化。优化后的电池箱模型在满足强度、刚度和低阶模态频率等要求的基础上减重5.3 kg,减重率达11.37%。

CF@PANI纳米复合材料的静电纺丝制备及其吸波性能

以聚乙烯吡咯烷酮为原材料,N,N-二甲基甲酰胺为助溶剂,首先通过静电纺丝与高温煅烧法制备出碳纳米纤维;然后,通过电沉积法,在碳纳米纤维表面完成苯胺单体的聚合反应,制备出核壳型碳纳米纤维@聚苯胺纳米复合材料。采用X射线衍射、扫描电子显微镜、傅里叶红外光谱、拉曼光谱以及X射线光电子能谱等测试手段对产物的物相、微观形貌、成分组成等进行了系统表征。对纳米复合材料的吸波性能测试结果表明:纳米复合材料综合吸波性能较单一碳纳米纤维有明显提升,其在4.42 mm厚度下,出现最强反射损耗-44.16 dB。通过研究纳米复合材料的多重反射、界面极化、导电损耗等对电磁波能量的衰减作用,阐述了多因素协同影响下的电磁波衰减方式。

复合材料树脂传递模塑成型工艺研究进展

汽车轻量化技术是现阶段及未来汽车制造领域所需要解决的艰巨任务,复合材料作为目前最有发展前景的轻量化材料之一,成为了人们关注的焦点。但其成型过程受多种因素的影响,如工艺参数和设备精度、树脂性能等其他因素都有可能造成最终成型构件发生固化变形,因而降低其力学性能。因此为提高构件的成型质量的同时,进一步推进复合材料成型工艺的研究进展,对复合材料成型工艺中的树脂基传递模塑成型工艺(RTM),一种环保、高效、低成本、高精度的闭模成型工艺进行了简单的概述,并总结了国内外学者对其进行的优化研究和成果。除此之外还重点介绍了几种以RTM工艺为基础衍生而来的工艺以及有关RTM工艺树脂开发与改性和工艺设备的研究成果及进展。最后对目前RTM工艺出现的问题进行了总结,并提出了相应的建议。

Al_(2)O_(3)粒度对CA_(6)轻质陶瓷材料结构与性能的影响

为研究Al_(2)O_(3)粒度对CA_(6)轻质陶瓷材料结构与性能的影响,本文以平均粒径分别为80、61、45和38μm的α-Al_(2)O_(3)为氧化铝源,以平均粒径为15μm的轻质碳酸钙为氧化钙源,采用发泡法结合原位烧成工艺,经1550℃保温5 h烧成后获得CA_(6)轻质陶瓷材料,研究不同粒度的Al_(2)O_(3)原料对其物相组成、显微结构和物理性能的影响。结果表明:随着α-Al_(2)O_(3)粒度的减小,CA_(6)轻质陶瓷的线收缩率、体积密度和热导率逐渐变小,显气孔率增大,压缩强度呈先增大后减小的趋势。综合考虑,以平均粒径为45μm的α-Al_(2)O_(3)为氧化铝源所制试样的综合性能较佳,更能满足使用需求,其显气孔率、热导率和压缩强度分别为87.8%、0.149 W·m^(-1)·K^(-1)和0.29 MPa。

稀土永磁同步电机的轻量化技术分析

阐述稀土永磁同步电机的优点,它是一种采用稀土永磁材料作为励磁的同步电机,具有无滑差、高效率、高功率因数等。探讨稀土永磁同步电机的拓扑结构设计和优化、稀土永磁同步电机机壳以及支撑架的结构优化。介绍稀土永磁同步电机集成化的特点。

马拉松跑鞋中底轻量化研究进展

随着马拉松运动的流行,轻量化跑鞋在缓震、支撑和舒适等性能基础上强化了轻便的特性,受到马拉松爱好者的青睐,具有广阔的发展前景。跑鞋实现轻量化,技术核心在于中底材料和结构的合理优化。本文回顾了跑鞋中底轻量化的发展历程,重点综述了国内外跑鞋中底材料的革新和鞋底结构轻量化设计的研究进展,并对马拉松跑鞋中底轻量化的研究趋势进行了展望,旨在为马拉松跑鞋中底材料的轻量化及结构创新设计提供新思路。

浅析汽车轻量化技术

随着“双碳”目标的提出和电动汽车的普及,汽车轻量化成为解决汽车能耗、续航里程和环境影响等问题的重要途径。综合分析了当前汽车轻量化技术的发展现状,强调了轻量化对于电动汽车性能、安全性、续航里程以及成本的重要性。主要介绍了包括材料轻量化(高强度钢、铝合金、镁合金、钛合金、塑料及复合材料、其他材料)、工艺轻量化(液压成形、热成型、激光焊接)以及结构轻量化(拓扑优化、形状和尺寸优化、多学科优化)的应用现状并对其发展趋势进行了探讨。综合而言,本文对于促进汽车轻量化技术的研究和应用具有一定的参考意义。