Due to their excellent properties, the requirement for materials with higher characteristics has transformed primary alloy into composite materials. Composites are particularly essential for various applications in numerous engineering purposes because of their superior mechanical, physical, and machining qualities. Compared to traditional materials, aluminum composite has various advantages and superior characteristics. To reduce production costs and obtain the desired properties, the researchers developed a hybrid aluminum matrix composite (HAMC), an AMC with two or more types of reinforcement. Further studies were conducted to improve the qualities and manufacturing processes of composites to improve their properties. Various methods are available to HAMC manufacturing, and different manufacturing methods result in different characteristics of HAMC composites, viewed from physical properties, mechanical properties, and production cost. In addition, differences in the type, size, and amount of reinforcement produce various hybrid composite properties, especially in the physical properties, mechanical properties, and tribological behavior of HAMC. This work presents a comprehensive review of recent progress in HAMC study with various reinforcement particles, manufacturing techniques, physical, mechanical, and tribological properties of HAMC. On the other side, this work provides discussion for application, challenges, and future work conducted for HAMC development.

The need for lightweight materials is increasing from year to year. In its application, lightweight and strong materials also need to be corrosion resistant. Corrosion resistance is an important property in automotive, especially in high humidity areas. Al6061-Sea sand material is a novel material that meets the mechanical standards required in the automotive sector. A previous study of Al 6061-sea sand conducted the mechanical properties of the composite. This current research focuses on the development of Al 6061 material with variations in weight fraction of sea sand reinforcement against the corrosion rate under the potentiodynamic method to determine the corrosion resistance of the composite material. The composite fabrication uses the electroless coating method on sea sand and the stir casting method with a melting temperature of 750°C. The agitation process used a four-bladed impeller for 10 minutes at 600 rpm with a stirring depth of ½ of the height of the molten metal. The tests include density testing, microstructure observation, and corrosion rate under the potentiodynamic method using an electrochemical potentiostat. The test result obtained the lowest corrosion rate results in 2% wt sea sand with a corrosion rate of 0.61875 mmpy. The increase in corrosion rate value is directly proportional to the addition of the weight fraction of sea sand.

Polymer materials are widely used due to their versatility; however, their vulnerability to fire is a significant concern, especially under electrical influences on engineered mechanical designs and marine structure applications. This study examines the fire resistance of a polypropylene (PP) blend using Glow-Wire Flammability Index (GWFI) and Glow-Wire Ignition Temperature (GWIT) tests. While previous research typically relies on flame-retardants to address flammability, this work proposes using a simple 1:1 weight ratio blend of two distinct PP types. This specific PP blend was selected to provide balanced material properties and improved processing consistency. The results from glow-wire tests were compared with previous findings to evaluate flammability performance. Our findings reveal that although the PP blend offers enhanced fire resistance compared to neat PP, it remains inferior to PP-containing flame-retardant additives. The outcomes suggest that this blended PP may be suitable for applications where mechanical properties, cost-effectiveness, and recyclability precede fire resistance, such as engineered automotive interiors, mechanical design of marine transportation, and low-risk electrical components in engineering infrastructure. This initial research contributes valuable insights into the fire behavior of PP blends. Moreover, it establishes a foundation for future investigations into polymer fire resistance, encouraging additional glow-wire testing on other polymer systems.

The increasing demand for lightweight material specifications has forced researchers to develop lightweight materials that are inexpensive, can be produced on a large scale, and are environmentally friendly. One solution that has been developed is an aluminum composite reinforced with sea sand. Indonesia has the second longest coastline in the world, which means that the country is rich in maritime resources, one of which is sea sand. The ceramic contents of SiO2, SiC, and Al2O3allow sea sand to be used as a reinforcement in aluminum composites for engineering purposes. The most effective manufacturing method of AA6061–sea sand composites is stir casting, but the homogeneity and distribution of particles are the main disadvantages of the stir casting method. Various factors affect particle distribution and homogeneity, one of which is the flow during the stirring process. The increase in turbulent flow in the stirring process affects the homogeneity and distribution of the particles. One way to create a turbulent flow when stirring is to add baffles. This paper examines the effect of adding baffles during the stir casting process on the mechanical properties of AA6061–sea sand composites. The mechanical properties of AA6061–sea sand composites were characterized using the Brinell hardness test according to ASTM E-10. The test results show that the addition of baffles during the stir casting process decreases the hardness of the AA6061–sea sand composites due to the turbulent flow that occurs. This makes the material more porous, which makes the AA6061–sea sand composites less hard. Doi: 10.28991/CEJ-2022-08-08-04 Full Text: PDF