Ceramic in the system Ca 2 P 2 O 7 –Ca(PO 3 ) 2 was obtained by firing cement stone fabricated from a powder mixture which included β-tricalcium phosphate β-Ca 3 (PO 4 ) 2 and monocalcium phosphate monohydrate Ca(H 2 PO 4 ) 2 ∙ H 2 O. The molar ratio Ca/P of the initial powder mixtures was set as Ca/P ≤ 1. X-ray phase analysis shows all ceramic samples after firing at 1000°C to include β-calcium pyrophosphate β-Ca 2 P 2 O 7 , and a sample of the ceramic made from a powder mixture with the maximum content of monocalcium phosphate monohydrate Ca(H 2 PO 4 )2 ∙ H 2 O also contained β-calcium polyphosphate β-Ca(PO 3 ) 2 . The obtained calcium phosphate ceramic with reduced firing temperature can be used to develop a resorbable matrix for tissue engineering structures.

Biphase ceramic containing hydroxyapatite Ca10(PO4)6(OH)2 and β-tricalcium phosphate β-Ca3(PO4)2 has been obtained from a uniform nanocrystalline calcium phosphate powder with the structure of apatite, synthesized from water solutions of calcium apatite and ammonium hydrophosphate with molar ratio Ca/P = 1.5 at room temperature without pH regulation. After firing at 1100°C the material contained 75% β-Ca3(PO4)2 and the grain size did not exceed 600 nm. It is suggested that the carbon formed in the interval 200 – 500°C, as a result of the carbonization of the organic components of synthesis adsorbed by particles of powder, be used as a physical barrier impeding intense mass transfer up to 800°C, which makes it possible to obtain an ultradisperse ceramic with grains smaller than 1 μm.

The properties of hydroxyapatite powder synthesized from calcium acetate and potassium hydrophosphate and hydroxide were investigated. The associated reaction product (ARP), whose basic component is potassium acetate, modifies the surface of the hydroxyapatite nanocrystals. The components of the ARP can play the role of a salt matrix by preventing coalescence of nanocrystallites and can also serve as a source for a sintering additive which is uniformly distributed due to adsorption during synthesis. A ceramic based on hydroxyapatite with a uniform microstructure and a maximum grain size of 300 nm was obtained by incorporation of sintering additives in the form of ARP at a temperature of 700°C. The ARP is the cause of different solid-phase processes and processes involving the liquid phase. The sites where these processes occur are the boundaries of the grains, which also restrains their growth.