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Antiballistics are used as personal protective equipment required by military and police personnel. They have been mentioned frequently in recent decades due to the increasing cases of war. Several studies have reviewed the development of antiballistic technology. However, there needs to be more discussion on and systematic reviews of the current milestones of antiballistic materials, testing, and procedures. In addition, compared to other fields, antiballistic studies are rarely carried out by public researchers because research on weapons is still a sensitive topic. Researchers who want to discuss antiballistics must cooperate with the country's defense and security agencies. This article aims to present a summary on and the development of scientific research on the theoretical concept of impact, the experimental approach for ballistic tests on advanced materials, the idealization of ballistic tests in computational mechanic simulations, and milestones of technical apparatus for ballistic performance measurement, over a period of more than 500 years. Thus, this analysis makes an excellent contribution to the field of antiballistics. This article review is based on hundreds of international journals and websites that are still active and can be accounted for legally. The results show that research related to antiballistics will continue to grow yearly.

The environment is a very important topic today as well as in the future. One source of air pollution that has the potential to harm health is the wear particles released by vehicle braking systems. If these wear particles come from hazardous materials, they could destroy human health and the environment. Based on these conditions, exploring more environmentally friendly materials to substitute hazardous materials as friction materials is necessary. In this study, brake linings were prepared from bamboo fiber and eggshell (ES) particles with various pre-treatment conditions. The composition of the material frictions consisted of phenolic resin, bamboo fiber, bamboo particles, ES particles, zinc, alumina, and graphite in the following: 35% phenolic resin, 10% graphite, 10% bamboo fiber, 10% alumina powder, 5% zinc powder, and 30% bamboo particles and ESs. This study focused on observing the mechanical and tribological behavior of friction materials when using ES particles as fillers. There are three stages to manufacturing friction material: a cold press, a hot press, and heat treatment. The optimization of the characteristics of ESs as organic brake linings was carried out using the Taguchi method and analyzed using data envelopment analysis-based ranking (DEAR). An interesting finding from this study was that when ES particles were calcined at 900°C for 120 min, the ES particle size was 200 mesh, and the ES volume fraction at 25% resulted in the most optimal brake lining performance. Calcination at 900°C for 120 min completely changed the CaCO3 phase to CaO. This study also shows that calcined ES particles have the potential to be developed as friction materials for environmentally friendly two-wheeled vehicles in the future. The produced brake linings exhibited hardness, a coefficient of friction, and specific wear rates of 92.82 HR, 0.32, and 4.43 × 10−6 mm3·N−1·m−1, respectively.

The aim of this study is to investigate the effect of alkaline treatment and addition of microcrystalline cellulose (MCC) on the density, tensile strength, elastic modulus, impact strength, and Poisson’s ratio of unsaturated polyester resin composites reinforced by cantala fibers (UPR-CFs). The fibers were immersed in alkaline solution of 6% NaOH for 0, 3, 6, 9, and 12 h. The composite had cantala fibers (CFs) and MCC volume fraction (v f) of 30 and 5%, respectively. The results showed that the alkaline treatment for 6 h resulted in the highest density, tensile strength, and elastic modulus of the composites, while the highest Poisson’s ratio was achieved in UPR-untreated CF composites. The addition of MCC filler also increased the density, tensile strength, and elastic modulus of the composite significantly. Both alkaline treatment and MCC addition did not significantly affect the impact strength. With the increase in the strength and modulus of elasticity, composites can be applied more widely to structures that bear higher loads.

Exposure to a humid environment can affect the behavior of brake lining composites. Considering the vital function of brake linings in controlling vehicle speed, environmental influences must receive serious attention. Exposure to lubricating oil that sticks to the brake lining can cause changes in performance during work. This study will investigate the dimensional stability of brake pad composites when exposed to engine oil and understand the physical behavior of material to facilitate appropriate handling. The brake pads in this study comprised 35% phenolic resin, 10% graphite, 10% bamboo fiber, 10% alumina powder, 5% zinc powder, 5% bamboo particles, and 25% eggshell particles. The manufacturing of brake linings involves three process stages: cold compaction, hot compaction, and post-curing. The samples were soaked in Federal Ultratec API SJ JASO MA engine lubricating oil for 12, 24, 36, and 48 hours. The results showed that the immersion time of the composite in lubricating oil did not significantly affect the dimensional stability of the composite. This result shows that the addition of calcined eggshell particles can improve the material's resistance to engine lubricating oil.

This review presents various types of epoxy resins and curing agents commonly used as composite matrices. A brief review of cross-linking formation and the process of degradation or decomposition of epoxy resins by pyrolysis and solvolysis is also discussed. Mechanical engineers are given a brief overview of the types of epoxy resin, which are often applied as composite matrices considering that they currently play a large role in the research, design, manufacturing, and recycling of these materials.

This study aims to review research the progress on factors that affect the 3D printing results of the fused deposition modeling (FDM) process. The review is carried out by mapping critical parameters and characteristics determining FDM parameters, the effects of each parameter, and their interaction with other parameters. The study started from the filament manufacturing process, filament material types, and printing parameters of FDM techniques. The difference in each section has determined different parameters, and the respective relationships between parameters and other determinants during printing have a significant effect on printing results. This study also identifies several vital areas of previous and future research to optimize and characterize the critical parameters of the FDM printing process and FDM filament manufacturing.

Thermosetting epoxy resin polymer with cycloaliphatic amines curing agent has been widely used for a composite matrix with carbon fiber reinforcement. The utilization was increased due to the superior performance of this epoxy resin compared to other polymers. However, a changing operational environment has potentially reduced composite performance, which most likely begins with matrix degradation. This research applies thermal treatment by the quenching process sequence to the epoxy resin matrix and its reinforced carbon fiber composite (CFRP). The composite is made by epoxy resin diglycidyl ether bisphenol-A, curing with cycloaliphatic amine as matrix and strengthening carbon fiber mat/woven. Three times quenching treatment was performed by heating the specimen around the glass transition temperature and then dipped immediately in fresh water. After quenching treatment, the epoxy resin shows a reduction in tensile strength and elongation. Under infrared observation, epoxy resin does not significantly show changes in functional groups. Investigation under X-ray refraction also indicates no difference in a crystalline structure; this epoxy resin stays in an amorphous form before and after quenching. In contrast to the matrix, the quenching treatment of the CFRP composite above the epoxy resin s glass transition temperature revealed an increase in the interlaminar shear strength (ILSS). The matrix ductility reduction after quenching should be carefully considered for application in the form of epoxy resin sheets or CFRP composite construction materials.

The utilization of eggshell (ES) waste as a composite filler has increased significantly in the last 5 years. This increase in usage took place due to its unique characteristics, which improve the properties of the resulting composite. Adding a weight fraction of ES particles into a composite can improve its mechanical properties, although not all studies have shown this phenomenon. Studies on these composites’ thermal and tribological properties are still limited, so more in-depth studies could be carried out. The degradation of composite performance due to friction or exposure to humidity and hot temperature is another area that is worthy of further study. In this work, we discuss changes in composites’ mechanical, thermal, and tribological properties associated with the addition of ES particles, examining both untreated particles and those treated with carbonation. This work can serve as a guide for the utilization of ES particles as an environmentally friendly composite material.

Natural fiber-reinforced polymer composites are a solution to growing environmental threats. This research used water hyacinth natural fiber and HDPE thermoplastic polymer. Natural water hyacinth fiber contains cellulose which can be used to create environmentally friendly and high-strength composites. The uneven distribution of natural fibers in the composite causes a decrease in the quality of the composite, both in terms of mechanical strength and morphological structure. Clumping and agglomeration are caused due to the incorporation of regenerated cellulose fibers in the composite. The treatment of water hyacinth natural fiber using a dispersion agent is intended to improve fiber distribution so that it is more evenly distributed. The addition of 0.5 ml of Dispersion Agent to water hyacinth natural fiber created the highest tensile mechanical strength of 26.2 MPa. The lowest mechanical tensile strength occurred in natural fiber composites without Dispersion Agent treatment of 19.5 MPa. Water hyacinth natural fibers added with the concentration of the Dispersion Agent did not show an increase in the tensile strength of the water hyacinth-HDPE natural fiber composites. Keywords: Water hyacinth, Mechanical Strength, Dispersion Agent.

Anti-ballistic is an indispensable personal protective equipment such as body armour for military and police personnel. This tool has received a lot of attention in recent decades due to increasing threats and insurgencies. Several studies have reviewed the development of anti-ballistic technology. However, there still needs to be discussion related to the development of anti-ballistics using UHMWPE (Ultra High Molecular Weight Polyethylene) and the contours of the surface of the UHMWPE. In addition, anti-ballistic studies are rarely carried out compared to other fields. This is because discussions or research related to weapons are still sensitive discussions. This study aims to determine whether the quality of body armour made using UHMWPE which one of the surfaces is given a specific profile, is better when compared to UHMWPE, which has no contours on all surfaces. UHMWPE material that is given a certain profile is one of the ideas chosen because it has high strength and aesthetic value, so it is expected to withstand bullet impact, comfortable and attractive when used. The antiballistic properties of UHMWPE given the diamond contour were obtained from numerical simulations using the finite element model (explicit dynamics) of ANSYS Workbench software. The two UHMWPE variants used in the multiplelayered configuration consist of UD UHMWPE sheets. Ballistic testing used a 7,62 mm calibre lead bullet with a velocity of 720 m/s. The material model of the bullet and UHMWPE plate used the Johnson-Cook plasticity model.

Al 6061-Al2O3 composite is a lightweight materials that can be used as an alternative material in automotive parts. T6 heat treatment is generally used on aluminium alloy series 6xxx . On T6 heat treatment process, material heated to temperature for obtaining a single phase of α, quenched and then continued by artificial ageing. Quenching is critical step because distortion can be occur in material. The aim of this research is to investigated effect of quenching agent and electroless coating treatment of Al2O3 in distortion at Al 6061-Al2O3 composite . The distortion was measured by dimensional change in the specimen. Coordinate Measuring Machine (CMM) was used to measured distortion based on coordinate change. Lower distortion are occur on 10E and 10N specimens. Electroless coating process on the reinforcement is more effective to obtain lower distortion on Al 6061-Al2O3 composite. The severity (H) of quenchant influenced distortion on specimen. Higher H value produce higher distortion on Al 6061-Al2O3 composite.

This study investigates the effects of Boric Acid (BA), H3BO3, and Sodium Silicate (SS), Na2SiO3, as single fillers on the mechanical and fire-resistant properties of Glass Fiber Reinforced Polymer (GFRP) composites. Various compositions of BA and SS were incorporated into the GFRP matrix, and the resulting composites were analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermo-Gravimetric Analysis (TGA), and Differential Thermal Analysis (DTA). The results demonstrate that BA significantly enhances the amorphous structure and mechanical strength of GFRP composites, with optimal performance at 10% BA content. In contrast, SS improves thermal stability but reduces mechanical strength at higher concentrations due to agglomeration. Fire resistance testing revealed that both fillers increase the ignition time and decrease the burning rate, with BA exhibiting superior performance. These findings suggest that BA is a more effective filler for improving the mechanical and fire-resistant properties of GFRP composites, while SS can serve as a complementary additive to enhance thermal stability. [ABSTRACT FROM AUTHOR]