Manufacturing and testing of long basalt fiber reinforced thermoplastic matrix composites

Flexural Properties and Low-Velocity Impact Behavior of Polyamide 11/Basalt Fiber Fabric Laminates

Environmentally friendly composite plates intended for load-bearing applications were prepared and systematically characterized in terms of mechanical performances and morphological features. Sample plates combining two extrusion grades of bio-polyamide 11, one of which is plasticized, and two basalt fiber fabrics (plain weave and twill architectures) were obtained by film stacking and hot pressing, and their mechanical properties were investigated by quasi-static flexural and low-velocity impact tests. The comparative analysis of the results, also interpreted by the bending damage analysis, through optical microscope observations, and impact damage analysis through visual inspection and indentation measurements demonstrate that, besides interfacial adhesion issues, the mechanical performance of the laminates need to be optimized through a careful selection of the constituents in the light of the final application. In particular, if the goal is a gain in impact strength, the use of the plasticized matrix is beneficial, but it brings about a loss in stiffness and strength that can be partially compensated by properly selecting a more performing fiber fabric architecture. The latter must also be easily permeated by the matrix to enhance the efficiency of stress transfer from the matrix. Overall, our results can be exploited for the development of bio-composites for particularly demanding applications.

Polypropylene/Basalt Fabric Laminates: Flexural Properties and Impact Damage Behavior

Recently, the growing interests into the environmental matter are driving the research interest to the development of new eco-sustainable composite materials toward the replacement of synthetic reinforcing fibers with natural ones and exploiting the intrinsic recyclability of thermoplastic resins even for uses in which thermosetting matrices are well consolidated (e.g., naval and aeronautical fields). In this work, polypropylene/basalt fabric composite samples were prepared by film stacking and compression molding procedures. They have been studied in terms of flexural and low-velocity impact behavior. The influence related to the matrix modification with a pre-optimized amount of maleic anhydride grafted PP as coupling agent was studied. The mechanical performances of the composite systems were compared with those of laminates consisting of the pure matrix and obtained by hot-pressing of PP pellets and PP films used in the stacking procedure. Results, on one side, demonstrated a slight reduction of both static and dynamic parameters at the break for specimens from superimposed films to ones prepared from PP pellets. Moreover, an outstanding improvement of mechanical performances was shown in the presence of basalt layers, especially for compatibilized samples.

Development and Mechanical Properties of Basalt Fiber-Reinforced Acrylonitrile Butadiene Styrene for In-Space Manufacturing Applications

A new basalt fiber reinforced acrylonitrile butadiene styrene (ABS) filament has been developed for fused filament fabrication (FFF, 3D printing) to be used in Mars habitat construction. Building habitats on Mars will be expensive, especially if all material must be shipped from earth. However, if some materials can be used from Mars, costs will dramatically decrease. Basalt is easily mined from the surface of Mars. This study details the production process of the material, experimental results from mechanical testing, and preliminary X-ray shielding characteristics. The addition of chopped 3 mm basalt fibers to standard FFF material, ABS, increased strength and stiffness of the composite material. By adding 25% (by weight) basalt fiber to ABS, tensile strength improved nearly 40% by increasing from 36.55 MPa to 50.58 MPa, while Modulus of Elasticity increased about 120% from 2.15 GPa to 4.79 GPa. Flexural strength increased by about 20% from 56.94 MPa to 68.51 MPa, while Flexural Modulus increased by about 70% from 1.81 GPa to 3.05 GPa. While compression results did not see much strength improvements, the addition of fibers also did not decrease compressive strength. This is important when considering that basalt fibers provide radiation shielding and the cost of adding basalt fibers to construction materials on Mars will be negligible compared to the cost of shipping other materials from earth. In preliminary digital radiography testing, it was shown that 77% of X-rays were shielded with 25% basalt fiber added (as compared to neat ABS). In small-scale 3D printing applications, the 25% fiber ratio seems to be the highest ratio that provides reliable FFF printing.