  The paper investigates friction and friction heat of the micronscale iron
under influences of velocity of the slider and temperature of the substrate by
using smoothed particle hydrodynamics simulations. In the velocity range of 10
- 100 m/s, change of friction coefficient via velocity well complies with
exponent or hyperbolic tangent form and friction coefficient begins to approach
a stable value of 0.3 at around a velocity of 50 m/s after a rapidly increasing
situation. Friction coefficient steady maintains over the temperature range of
200 - 400 K at each velocity of 10, 50 or 100 m/s. Friction heat is detailed
analyzed via sliding time. Change of temperature of the system via sliding time
well complies with sigmoidal functions, an exception of that of the particle
layer directly causing friction. The layer causing friction has the highest
steady temperature and its temperature rise is the largest one. The temperature
rise is found to be dependent on increment of the initial temperatures of the
substrate and the slider while the incnt does not efect on configration of the
slid time - temperature curve
