Duplicar registro e modificar a copia!

procedure TForm1.clonar;
  begin
tbrecebe.First;
while not tbrecebe.Eof do
begin                                        
  tb_copia.Append;
  tb_copia.CopyRecord(tbrecebe);
  tb_copia.Post;

  tbrecebe.Next;
end;
end;
 
procedure TForm1.Btsalvar(Sender: TObject);
var
x:double;
y:double;

begin
x:=StrToFloat( nt_volume.Text) ;
if x >= 1 then
begin
y:=1;
tbrecebe.FieldByName('volume_imp').Value:= (floattostr (y) + '/' +floattostr( x )) ;
postar;
repeat
     begin
     y:=y+1;
     clonar;
     tb_copia.Edit;
     tb_copia.FieldByName('volume_imp').Value:= (floattostr (y) + '/' +floattostr( x )) ;
     tb_copia.Post;


     end;
     until  y = x   ;
    desabilitar; //desabilita os edites

end;
end;