246Mechanical activation (MA) is widely used to improve the efficiency of solid state reactions [1,2], including SHS in low caloric green mixtures [3][4][5][6][7][8]. Despite earlier attempts [3,9,10], the processes lead ing to formation of mechanocomposites (agglomer ates) still remain obscure because of rich variety of accompanying physicochemical events.In continuation of our previous studies [11,12], in this work I made an attempt to reveal a relationship between the inner layered structure of mechanocom posites and temperature characteristics of thermal explosion in activated reactive Ti-Ni mixtures.MA of equiatomic mixtures of commercial Ti (PTM1 brand) and Ni (PNE1 brand) powders was carried out in an M 3 planetary mill under Ar (45 g, interrupted activation for 30 s periods + 5 min hold ing in air). MA was performed until formation of mechanochemical products as detected by XRD. In all cases, powder weight was 80 g, ball diameter 5 mm, and mill/ball ratio 1 : 5.Thermal explosion in activated mixtures was initi ated in a 5 L constant volume reactor under Ar. Tem perature profiles were taken with a chromel-alumel thermocouple. Thus obtained thermograms were used to determine ignition temperature T ig and maximum temperature T max . Starting powders and combustion products were characterized by SEM (Philips SEM515), optical metallography (Axiovert 200M), and XRD (DRON Um). Figure 1 shows the averaged (over 5-7 experimen tal runs) values of ignition temperature T ig and maxi mum combustion temperature T max vs. duration (τ) of MA. A general trend is a gradual decrease followed by some fluctuations at τ = 4-6 min.At the very beginning of MA, powder particles lose their initial shape. They get comminuted and via freshly cleaved surfaces stick together thus forming laminated agglomerates, also termed as mechano composites (Fig. 2a). The processes of their fracturing BRIEF COMMUNICATIONS