The bone, being an essential tissue in the human body, not only protects the organs inside the body but also provides mechanical support, haematopoiesis, mineral storage and mobility. Although bone may regenerate and heal itself, significant bone defects caused by severe trauma, tumour removal, malignancy, or congenital diseases can only be corrected via bone grafting. Bone biomaterials, also known as bone graft alternatives, have seen an increase in demand in recent years. Over 2 million procedures are performed in the United States each year to restore damaged/fractured bones by grafting. The number of patients in China with reduced limb function owing to bone abnormalities has risen to 10 million. Traditional bone defect repair materials include autogenous bone, allogeneic bone, xenogeneic bone, decalcified bone matrix, bioceramics, and metal materials, which are easily available and processed. Calcium silicate (Ca-Si) ceramic is among the most promising bioceramics for these purposes due to their amazing characteristics such as bioactivity, biocompatibility and osteoinductivity. Unfortunately, its high biodegradation rate along with its poor strength represents major limitations that limit its use in clinical applications significantly. In light of the above, this article briefly discussed the different types of bone substitute materials, the properties of Ca-Si ceramic, the advantages, limitations and potential solutions to overcome these drawbacks and its biomedical applications such as orthopedic, dental, wound healing and drug delivery.

The main objective of this work is to recycle unwanted industrial waste in order to produce innovative nanocomposites with improved mechanical, tribological, and thermal properties for use in various industrial purposes. In this context, powder metallurgy (PM) technique was used to fabricate iron (Fe)/copper (Cu)/niobium carbide (NbC)/granite nanocomposites having outstanding mechanical, wear and thermal properties. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) examinations were used to investigate the particle size, crystal size, and phase composition of the milled samples. Additionally, it was investigated how different volume percentages of the NbC and granite affected the sintered specimens in terms of density, microstructure, mechanical and wear properties, and coefficient of thermal expansion (CTE). According to the findings, the milled powders included particles that were around 55 nm in size and clearly contained agglomerates. The results showed that the addition of 4 vol.% NbC and 8 vol.% granite nanoparticles caused a reduction in the Fe–Cu alloy matrix particle sizes up to 47.8 nm and served as a barrier to the migration of dislocations. In addition, the successive increase in the hybrid concentrations led to a significant decrease in the crystal size of the samples prepared as follows: 29.73, 27.58, 22.69, 19.95 and 15.8 nm. Furthermore, compared with the base Fe–Cu alloy, the nanocomposite having 12 vol.% of hybrid reinforcement demonstrated a significant improvement in the microhardness, ultimate strength, Young’s modulus, longitudinal modulus, shear modulus, bulk modulus, CTE and wear rate by 94.3, 96.4, 61.1, 78.2, 57.1, 73.6, 25.6 and 61.9%, respectively. This indicates that both NbC and granite can actually act as excellent reinforcements in the Fe alloy.

More focus has recently been placed on enhancing the strength, elastic modulus, coefficient of thermal expansion (CTE), wear and corrosion resistance, and other qualities of aluminum (Al) alloys by varying the quantity of ceramics added for a range of industrial uses. In this regard, Al-4.2-Cu-1.6Mg matrix nanocomposites reinforced with nano-ZrO₂ particles have been created using the powder metallurgy approach. The microstructure and particle size distributions of the produced powders were analyzed using a diffraction particle size analyzer, XRD, TEM, and SEM. To achieve good sinterability, the powders were compacted and sintered in argon. The sintered nanocomposites' mechanical, elastic, and physicochemical characteristics were measured. Additionally, the behavior of corrosion, wear, and thermal expansion were examined. The results showed a decrease in the particle sizes of the Al-Cu-Mg alloy by adding ZrO₂ nanoparticles up to 45.8 nm for the composite containing 16 wt.% ZrO₂. By increasing the sintering temperature to 570 °C, the densification of nanocomposites was enhanced. Also, the coefficient of thermal expansion and wear rate remarkably decreased by about 28 and 37.5% by adding 16 wt.% ZrO₂. Moreover, microhardness yield, strength, and Young’s modulus were enhanced to 161, 145, and 64%, respectively, after adding 16 wt.% ZrO₂. In addition, increasing the exposure time was responsible for decreasing the corrosion rate for the same sample.